A week of good or bad matchups can make all the difference in Fantasy basketball. And before you make any kind of claim on the waiver wire or set any lineups for Week 21, you need to see what NBA Fantasy expert Mike Barner has to say. 

Barner is one of the most respected voices in the industry, whose work has appeared in Sports Illustrated and on Yahoo, RotoWire and KFFL. He's also been featured on ESPN Radio. He digs deep into the data, examining team trends and projecting game outcomes. If there's anybody who can spot an edge in a matchup or identify a player in position to break out, it's him.

Now, Barner has studied the upcoming NBA schedule and is sharing his best and worst matchups for Week 21 of Fantasy basketball. They'll help you figure out who to sit, start, add, and drop this week. 

One thing we can tell you for this week: Barner is giving a boost to several Memphis Grizzlies players because of their upcoming five-game schedule. 

"The Grizzlies are one of four times that will have the benefit of playing five games," Barner said. "Even more appealing is that three of those contests will come against teams who rank inside the bottom-10 in the league in defensive rating. Having two back-to-back sets in a week is always a concern, but the Grizzlies haven't been a team to rest players."

Barner has also identified a sleeper who NEEDS to be in your lineup this week because his minutes continue to increase due to injuries. This player should return massive Fantasy numbers in multiple categories, and he's most likely on the waiver wire in your league right now.

So who should you start and sit this week? And which overlooked sleeper could lead your team to victory? ... Join SportsLine right now to get Mike Barner's best and worst Fantasy basketball matchups for Week 21, all from one of the most respected voices in the industry!