The 2021 NBA free agency class is headlined by some of the top players in the game, such as DeMar DeRozan and his former Toronto Raptors teammate Kyle Lowry, who are set to be up for grabs this summer. Then there are players like Steven Adams, who has the ability to play an integral role in the setup of a championship-contending team.2021 NBA Free Agency: 5 names that franchisees need to keep a watch on in the off-season despite their non-superstar statusRecent NBA Championship-winning teams have proven that the squad should be an ideal mix of superstars and role players. The 2019-20 LA Lakers had such a blend, with Dwight Howard, Kentavious Caldwell-Pope and Kyle Kuzma complementing LeBron James and Anthony Davis well.The upcoming NBA free agency has several underrated gems of similar ilk. W take a look at five underrated free agents who could be in demand this summer.5) John Collins (Atlanta Hawks)Atlanta Hawks' John CollinsAtlanta Hawks' young power forward John Collins was involved in various NBA trade rumors throughout the campaign, but will see out the season with the team that drafted him. Collins had a solid season for the playoff-bound Hawks, putting up 17.6 points and 7.4 rebounds on 55% shooting from the field, apart from racking up a block per game.2017 NBA Draft Class Rankings (John Collins) 19th Overall PickTotal Points – 3888 (5th) Total Rebounds – 1995 (3rd)FG% - 56% (4th) *min 50 games3PT% - 37.5% (5th) *min 50 gamesMinutes Per – 28.6 (7th)Points Per – 16.5 (4th)Rebounds Per – 8.5 (1st)Win Shares – 22.5 (4th) pic.twitter.com/x9nS4ES2Oe— The Official Atlanta Hawks Sports Network (@AtlantaHawksSN) May 10, 2021Collins is an offensive-minded player with a good post game and a respectable jump-shot, making him one to watch out for in the upcoming NBA free agency.4) Jarrett Allen (Cleveland Cavaliers)Cleveland Cavaliers' Jarrett AllenBeginning the 2020-21 season on a championship contender, promising center Jarrett Allen finished it on a lottery team. Allen had a productive year, as he averaged 12.8 points, 1.4 blocks and 10 rebounds on 61.8% shooting. Allen is one of the few young centers adept at playing on both ends of the floor, and he would be a brilliant addition to any franchise in the summer.Report: NBA agent says Jarrett Allen could draw contract at around $25 million per year https://t.co/1lrwDJ3BNx— NBA Central (@TheNBACentral) May 16, 2021With his time in Cleveland probably coming to an end, Allen should be looking to bag a rewarding contract with a playoff team in NBA free agency.Also Read: NBA Rookie of the Year 2021: Latest Power Rankings - May 17th, 2021