Fantasy sports and overreactions go hand-in-hand. Sometimes you've got to go all-out for a free agent after just a one-game sample size. Often, you end up dropping him the next week. It's just the nature of the game. 

But when it comes to the higher-caliber players on your team, then the risks become great. Buying low and selling high become the path to either a Fantasy championship or the bottom of the standings. With all that in mind, let's take a look at some of the early-season surprises for guys you drafted as starters to find out whether this kind of production is sustainable.

Brandon Knight: 19.7 points, 6.7 rebounds, 9.0 assists per game
Buying it? Kinda sorta

We've always known Brandon Knight is an athletic scorer and an above average backcourt rebounder. But a floor general? That's news to the rest of the league. After a stellar 13-assist opening night, he has come back to earth with totals of eight and six to follow. But watching film of these three outings has convinced me that he'll have a career-year in the assist column, which isn't saying anything huge since he's never averaged more than five per game.

His court vision has improved, and he's now seeing the passing lanes that will complement his quick first step. His dimes so far this season have been a healthy balance of drive-and-dish 3s, dump offs for dunks and cutting layups. Say what you want about the Bucks, but they do boast a bevy of willing shooters (O.J. Mayo, Jared Dudley, Khris Middleton, Jabari Parker ) and springy finishers (Larry Sanders, John Henson and Giannis Antetokounmpo). Knight's jump shot might still be unreliable, but if Jason Kidd keeps the ball in his hands, there's no reason to think six-plus assists per game isn't sustainable.

Target if you want to sell high on Knight: Ty Lawson

A week ago you'd have done this in a heartbeat. Don't let Knight's hot start and Lawson's struggles stop you now.

Klay Thompson: 29.7 points, 3.3 made threes, 53.7 percent from the field per game
Buying it? Ehhhhhhhhhhh

I've never been a huge fan of Klay's game, so maybe that's coloring my perception, but he just doesn't seem like the kind of player who's going to consistently score like James Harden and Kevin Durant. He's tall, athletic and possesses one of the most automatic jumpers in the game, but I just don't see what he's doing differently this year to make you think he has improved leaps and bounds. Other than the trademark quick-trigger 3s, he's still taking tough runners off the dribble. I will say he's being much more patient and using his size rather than trying to rush his takes to the basket, which is encouraging.

Still, we've yet to see the Warriors at full strength, and Thompson hasn't really shown us he can produce peripheral stats other than a sterling free throw percentage. I'm sure coach Steve Kerr is fine with that because the Warriors only need him to score. But we need to see him do more to consider him a breakout. This is just doing what he's always done at an improbably successful rate. He averaged 25.0 points per game on 65 percent from the field through the first three games last year, so it's not like this kind of hot stretch is unheard of.

Just to give you an example of how crazy his numbers are so far: The only players in NBA history to average more than 24.0 points and 3.0 made 3s per game on greater than 45 percent from the field for a whole season are Ray Allen and Klay's teammate, Stephen Curry. I'm just not of the belief that Klay possesses that kind of talent. 

Target if you want to sell high on Thompson: Damian Lillard  

Lillard is banged up and has had a dreadful start to the season, but he'll be right there with Thompson in 3s by the end of the season and has a much higher assist potential. 

Joe Johnson: 22.0 points, 6.7 rebounds, 5.0 assists per game
Buying it? To some degree

He's due to regress, but you can see Johnson beginning to embrace a role as a do-everything type of player. His days of high-usage chucking seem to be over, so getting a more balanced line out of one of your value picks has to be nice to see. I targeted Johnson in lots of mock drafts this year just because I saw there was somehow room for him to grow with this Nets team. He has become a rare power guard in today's game, using his strength and size to park in the lane and find open shooters. Johnson has been looking more like Gordon Hayward and less like Rudy Gay so far this year, which seems like a much better way for him to be effective in Brooklyn. 

As crazy as it sounds, he's easily the most versatile player on the Nets roster. It's hard to bet on a 33-year-old gunner turning into a glue guy, but if Johnson embraces doing the little things like rebounding and facilitating, he'll be one of the biggest values in Fantasy. 

Target if you want to sell high on Joe Johnson: Brandon Jennings

There's no way D.J. Augustin can completely overtake his job. Shipping away Johnson seems worth it if you can get a guy who averaged 15.5 points, 7.6 assists and 1.9 made 3s per game last season.