On Sunday the Patriots will make their eighth Super Bowl appearance this century and if all goes well they'll take home their sixth Lombardi Trophy and their third in the last four years. The first title came after the 2001 season, back when Tom Brady was a little known fresh-faced 24-year old and Bill Belichick was in just his second season as the Patriots coach.

Almost everything has changed in the 16 years since, though the constants -- Brady and Belichick -- remain the cornerstone of that sustained success. As long as the coach and quarterback remain, the organization will always be among the league's best. But with 18 players set to hit free agency in a few weeks, the Patriots could be a completely different team in 2018.

How different? Let's take a look at some of the biggest names.

Nate Solder, left tackle

The team's first-round pick in 2011, he has started 95 regular-season games in his seven seasons, including 13 in 2017. Solder was one of the NFL's best tackles in 2016 but has struggled this season, ranking last among all Patriots starting offensive linemen, according to Pro Football Focus' grades. But Solder has also been dealing with things much bigger than football; in 2015, his newborn son was diagnosed with a rare form of pediatric cancer. Now 18 months old, Hudson Solder is doing better but serious challenges remain.

Belichick has insisted that Solder put family first.

"Nate is just someone of the highest character," the coach said this week, via USAToday.com. "We all respect Nate for what he has done with Hudson, how he is always there for him. We understand there are times he has to miss something."

Meanwhile, Solder's professional future in New England remains unclear.

"I don't know [what will happen after the season]," Solder told reporters this week. "I hope [to return to New England]. I love the people here and it's a great organization, but I don't know what's going to happen."

He added: "I'm very committed and focused to what we're doing right now. I think there will be time for that in the future, so I'll leave it at that."

Malcolm Butler, cornerback

Three years ago, Butler wasn't a household name. That all changed when he intercepted Russell Wilson in the final moments of Super Bowl XLIX to seal New England's fourth Lombardi Trophy. A restricted free agent in 2017, Butler earned $3.9 million after a reported offseason trade to New Orleans never materialized. Now 27, Butler may have priced himself out of the Patriots' plans. He ranked fifth among all cornerbacks in 2016, according to PFF, but stumbled to 48th this season. In fact, he was the lowest-rated Patriots' defensive back with at least 700 snaps. He can earn $10 million-plus annually on his next contract but it almost certainly won't be in New England.

Danny Amendola, wide receiver

The Patriots lost Julian Edelman to injury in August but they didn't seem to miss his 98 catches and 1,106 receiving yards from the previous season. The offense was the league's best in 2017 (first in passing offense, third in rushing offense), according to Football Outsiders. Amendola has been a big part of that postseason success. CBSSports.com's Sean Wagner-McGough wrote about this earlier in the week:

After averaging 4.1 catches, 43.9 yards and 0.1 touchdowns per game in the regular season, Amendola is averaging nine catches, 98 yards and one touchdown per game in the playoffs. According to Pro Football Focus, Brady accumulated a 103.1 passer rating when targeting Amendola in the regular season. In the playoffs so far, Brady has a 134.1 passer rating when targeting Amendola. Brady has thrown only four incompletions in Amendola's direction out of 22 total attempts in the playoffs, which makes for an 82 percent completion rate. According to PFF, Amendola has caught more passes on third third (24) than every other Patriots receiver combined (23) in both the regular season and playoffs.

But at 32, Amendola is a year older than Edelman, who will be healthy for the 2018 season. And with Brandin Cooks, Phillip Dorsett and Chris Hogan all under contract, the Patriots may be willing to part ways with Amendola after previously restructuring his contract three times in five years.

Dion Lewis and Rex Burkhead, running backs

Lewis was the NFL's best back in terms of total value, and ranked second in value per play, according to FO, but the Patriots just gave James White a modest three-year contract extension (three years, $12 million) last offseason and Belichick isn't known for paying running backs big money. But Lewis is more than just a runner; in addition to his 896 rushing yards (5.0 YPC) and six touchdowns, he had 32 receptions for 214 yards and three more scores. He ranked 12th in receiving among all running backs, just behind Le'Veon Bell.

Will his versatility be enough to entice the Patriots to pay him?

Burkhead is a similar player; in 2011 fewer snaps, he ran for 264 yards (4.1 YPC) and five touchdowns and added 30 receptions for 254 yards and three more scores. He ranked seventh among running backs with fewer than 100 rushing attempts, and he was ninth in receiving among running backs, three spots ahead of Lewis.

Matthew Slater, wide receiver*

A 2008 fifth-round pick out of UCLA, Slater has exactly one NFL reception. It came in 2011 and went for 46 yards. But the seven-time Pro Bowler has spent his entire career in New England for one simple reason: He's one of the league's best special-teams players. At 32, Slater continues to play at a high level, and given that his cap hit was just $1.6 million in 2017, it's reasonable to think the Patriots would bring him back.

Other notable free agents

Cornerback Jonathan Bademosi, offensive tackles Cameron Fleming and LaAdrian Waddle, special teamer Nate Ebner, pass rusher James Harrison.