2015 was a nightmare for the San Diego Chargers. Amid speculation of the team moving to Los Angeles, the Bolts limped their way to 4-12, a difficult thing to do when there's a franchise quarterback like Philip Rivers on the roster.

Despite the struggles, the San Diego QB remains optimistic about the coming season. Rivers, who worked with Gillette on their Father's Day "Go Ask Dad" campaign, told CBSSports.com in an interview that he sees a bounceback for the Chargers in the coming year.

Rivers sees big things ahead for San Diego in 2016. USATSI

That's in large part to the addition of some high-quality players in free agency (Brandon Mebane on defense, Travis Benjamin on offense) and in the draft. In particular, Joey Bosa stood out to Rivers during OTAs, with the quarterback saying he thinks the Chargers "nailed" the pick of the Ohio State defensive end.

"We feel good about where we are and we feel good about the pieces we added in free agency. And I think defensively you think about Brandon Mebane and offensively you go get Travis Benjamin and in the draft you draft Joey Bosa," Rivers said. "And I know it's still a little early to say but I think we nailed that pick at No. 3 overall. Bringing in tight end Hunter Henry, a handful of other things. Matt Slauson, we signed late from the Chicago Bears at center, looks like he's penciled in there at center. So we're better.

"I know everybody gets excited in OTAs but we're better than we were at the end of last season. We're healthy and we added some good players."

What's interesting about Bosa is the fit for him in John Pagano's 3-4 scheme. Bosa, who spent most of his time rushing the passer at Ohio State, was pegged as more of a 4-3 end and less of a fit for San Diego at No. 3 overall.

Will Bosa be a fit in San Diego's defense? USATSI

The Chargers took him, though, because he was the top player on their board. Bosa's run-stopping abilities make him fairly scheme-versatile, and Rivers doesn't believe what the Bolts run will matter at all for the rookie lineman.

"I think it's a little bit misleading when you see teams, are they a 4-3 or a 3-4 -- guys line up in so many different fronts. Our guys when we're in the 3-4 personnel, they're mostly in an under front, and he's been all over the place in these OTAs, we've used him everywhere," Rivers said. "But John Pagano, he's in nickel and sub defenses over 70 percent of the time and that's where Joey is probably gonna fit in right there at the end. Shoot, I saw him on some college tape playing 3-technique in a 4-3. He's very versatile so I don't think that's an issue. I think [GM] Tom Telesco's philosophy is just get good football players and we'll figure out where they go. We don't have to fit a certain, exact scheme, and I think Joey fits that mold."

Rivers notes this, but it's OTAs. Everyone feels good about where they are in May and June. But the Chargers have to feel better about where they are relative to the end of last season, when they limped to a close and were fielding a roster that was destroyed by injury.

With all the hype the Raiders are getting and all the attention the Broncos get after winning a Super Bowl, the Chargers are a sleeper to win the division. If they do, it's not unreasonable Bosa could be a big part of it. Rivers certainly would be.

Read the rest of the interview with Rivers about the Chargers in 2015, their expectations for this coming year, some of their additions and what it's like being a dad of eight (!) below:

At any point did you guys you were a little snakebit? You might've had one of your kids out there playing offensive line at one point it felt like

In many ways, yes. We kept losing close games. We get a ball batted in Pittsburgh that's probably going to run for a touchdown with like two minutes left. And we kick a field goal and they score with five seconds to win. In Chicago we're ahead the whole game -- I could go on and on.

We could not win a close game, and there's a lot of factors in that, both in getting a stop defensively and executing offensively down the stretch. But we had so many guys hurt up front. It was just a revolving door. That's no excuse, that's just truth.

And we didn't play as well as we needed to when the game was on the line. I don't think there's any lost confidence. I think getting healthy was the first thing that was going to make us a better team. And then adding some key pieces is going to help. Guys who were in places that they played a lot of football, they've won where they've been and that can bring some good culture and things and hopefully get us going.

Whisenhunt returns after a head-coaching stint in Tennessee. USATSI

How much of a transition is it bringing Ken Whisenhunt back? Is it easy sliding right back in with him [as your offensive coordinator]?

No we kept -- it's exactly the same for the most part. There's always some tweaks here and there that coordinators like or the way they like to call plays or formations. We kept it from what he installed in 2013, which was totally brand new for me to what we did with Frank [Reich]. It's the same, it's the same offensive, plus or minus a few things. So that's been smooth.

And there are some guys who were on the team with him in '13, there are some that aren't, that don't know him like some of us do. But he's a great manager of people, he has a great command of the room and he's got us off to a great start this offseason.

Quarterbacks learn under other quarterbacks, but how about tight ends learning under another. I think it's interesting Hunter Henry gets to learn behind a sure-fire Hall of Famer in Antonio Gates. How much does that help Henry?

I think that's awesome because Gates is so unique in the way he does things. There are so many things you can coach on the chalkboard, as they say, and draw up the routes and those things. There are certain things you can't coach, you've got to watch a guy do it. How did he get open on that route? That's not how's it drawn, but he just has a feel for it and has been doing it for a very long time.

Hunter, I can tell very early on he's going to be a technique-sound guy. He's going to run crisp routes and he catches the ball really well, but he can add to that with a natural feel and a playmaking ability and kind of a knack for getting open and watching Gates who's one of the best at, will certainly help him. He's had a good 10 OTAs and Hunter's been good -- when you lose a guy like Ladarius Green, who was on the field a lot for us, Hunter's going to have to step in and play early.

Rivers has a secret weapon for J.J. Watt this year. USATSI

Derek Watt is another rookie you drafted -- when you play the Texans in November, does having Derek on the field make it better or worse for you with his brother [J.J. Watt of Houston]?

I don't know -- if we put his brother out there it might make him more motivated. That's guys something else. We've already kind of teased Derek about that and said we'll try and set up where he can block him once or twice. I don't know that's the matchup we want though. They're not quite the same size. We kind of went with a hybrid tight end to play fullback the last few years so we'll see.

He seems to do things well, but it's so hard ... inside linebackers when you're running leads and ISOs and full downhill when you're in helmets and T-shirts. You kind of go, yeah, I don't know -- he looks good but we'll see how it is when it really gets going. It's hard to really tell until you get to training camp.

You're working with Gillette for Father's Day. Family man, obviously, plenty of kids, close with your father, a brother who plays football -- tell us a little bit about the campaign.

Father's Day Gillette is really putting the spotlight back on the dads. It's a "Go Ask Dad" campaign. It's encouraging teens, no matter where they are, what they're doing, to go ask Dad. It seems in this day and age our teens are going to the internet to learn all the things we would ask our dads. How to tie a tie, how to shave, all those little things. I ran into someone the other day and he said his son called and he had a flat tire and he said I'm looking it up on the internet. And the dad said I'd come help.

All the valuable lessons I learned from my dad, little questions to big, and that's what I want my children to do. So that's really the campaign in the nutshell. You can get the info on the internet but you can't get that personal touch that you get from your dad that knows you best.

Go to Gillette's YouTube page to see the video. The Gillette Shave Club is about the best present you can get [for your father]. I get told by all my little ones, the little girls, that you've got to shave because the whiskers hurt.

Would your kids make you more or less likely to play football in your 40s?

I don't think it will do either one. If I'm healthy and the Chargers still want me to hang around, I'm going to go until they tell me to get out.

Philip Rivers, family man. USATSI

What sport are you encouraging your kids to play?

Well, my oldest son is all over football. And that's just fine. He loves basketball, and I think with the NBA Finals he thinks he's Steph Curry in the backyard. And I was fussing at him because I said he needed to work on his shot. We were playing pig in the backyard and I said, 'Work on your shot and follow through and quit aiming and kind of throw it.' And he said, 'Well, Steph Curry doesn't hold a follow through.'

And that's what I'm up against: I'm trying to teach my eight-year-old to shoot.

Harder to raise: a boy or a girl?

I think girls. I think girls. I'm just getting into the teenage years. My oldest will be 14 here in about four weeks so I think, yeah, girls definitely more challenging. And I'm fixing to really find out here. I'm going to have three that are teenagers at the same time. It'll be quite the challenge. But it's good. Very thankful and blessed but definitely I think girls are more challenging.

What is the best Father's Day gift you've ever gotten?

When you have as many as we do it's hard to remember what was Father's Day and what was Christmas and what was birthday, you know? I've always loved the homemade things they come up with, whether it's the little [rubber band] bracelets they make or they make a key chain. Certainly love all the homemade cards. My son would always draw the field goal post and the ball going through it and like a lightning bolt or something. There's one of those every Father's Day, that's for sure.