Former NBA player Matt Barnes rallied behind Arkansas head coach John Calipari's comments about the current state of college basketball. In a guest appearance on "Nothing Personal with David Samson" on Tuesday, Calipari said 18-year-old athletes are having a hard time being recruited by college teams.The longtime head coach claimed that one of his freshmen players had to face a senior who was 26 years old. Calipari pointed out that athletes tend to stay longer in college to play due to NIL deals.Matt Barnes agreed with Calipari and called out the NCAA in an Instagram post on Thursday."@ncaa y’all gotta fix this mess. Get these old ass men outa college sports. 5-6yr max.. These grown ass men taking opportunities away from kids trying to get to the next level," Barnes said."News Flash if you are 24 and older the likeliness of you going pro, Is VERY UNLIKELY hate to break it to you!!" he continued. "Unless you’re a QB for some reason they draft old ass QBs. But for the rest of you get your degree & move on, life is waiting on you..Stop clogging up the pipeline." View this post on Instagram Instagram PostThis wasn't the first time Calipari had expressed concern about college athletes staying longer due to NIL deals. In a guest appearance on "The Jim Rowe Show," Calipari said college basketball leagues should fix transfer portals.Last season, Ebrima Dibba of Cleveland State was one of the oldest players in the NCAA. He was born in May 1999, which makes him 26. Sola Adebisi of The Citadel is projected to be the oldest player next season. The senior was born in April 2000 and will be 26 by next year.Matt Barnes expressed concern for college basketballMatt Barnes also weighed in about college basketball in a December episode of his "All The Smoke" podcast. Barnes was concerned about the future of college hoops, given that some players were rushing to get into the NBA before they were ready."I just wonder what the future of college basketball is going to be," Barnes said (26:56). "Because it used to be must-watch TV, March Madness used to be the s**t and it's still cool, but it's just not what it was because there are so many other avenues for kids."Whether it's one-and-dones or going overseas for a year and getting to the league, I think everyone is in such a hurry to get to the NBA when they're not necessarily ready."Barnes then went on to blame the NBA for drafting players based more on potential than actual production.In Barnes' case, he attended college for four full seasons. He suited up for UCLA and gradually developed into a productive college veteran. In his final season for the Bruins, he averaged 13.5 points, 6.2 rebounds and 3.5 assists through 31 games.It was a significant improvement from when he was a freshman, when he averaged 3.9 points and 2.9 rebounds.After entering the NBA at 23 years old, Barnes went on to have a productive 14-year pro career, winning the title in 2017 with the Golden State Warriors.