By Matthew Geagan, CBS Boston

BOSTON (CBS) — The Celtics had a season full of disappointment in 2021, but no one was more disappointed — or disappointing — than point guard Kemba Walker. Despite Boston’s attempts to manage the balky left knee that has plagued him since the early parts of 2020, the 31-year-old could not stay healthy when it mattered most.

READ MORE: Celtics Reportedly Sign Garrison Mathews To Training Camp Roster

Boston’s season ended Tuesday night with a Game 5 loss to the Brooklyn Nets. Walker couldn’t suit up for that game — or Boston’s Game 4 loss — because of a medial bone bruise in his left knee. It wasn’t even the knee ailment that caused the Celtics to sit Walker on the second leg of back-to-backs throughout the regular season (in addition to various other nights off), but a whole new injury that Walker said he suffered when he landed funny in Game 2.

Walker’s inability to stay healthy during the season and in the playoffs basically blew up any chance at the C’s forming some chemistry throughout the campaign. He wasn’t the only Celtic to deal with injuries during the season, but his overall health concerns paint a troubling picture for his future, considering he’s Boston’s highest paid player over the next two seasons.

“The last thing you want to do is be injured and not be there in the playoffs for your teammates. It’s tough, very tough. I’m a competitor and I love to play basketball,” Walker said after Game 5. “I do anything I can to help teammates win a game, and because I couldn’t do that I’m really down. It’s a tough situation, but I have to look ahead. I want to continue to get healthy and get better. That’s my goal.”

READ MORE: Celtics Reportedly Sign Guard Ryan Arcidiacono To Training Camp Roster

As down as he was when he spoke with reporters over Zoom on Tuesday, Walker remains upbeat about his future. He’s confident that he’ll be healthy next season, thanks in large part to the extra time off that awaits him this offseason.

“I’m planning on a big summer and getting myself feeling good again. It’s been awhile since I’ve really had time off,” he said. “This is an important time for me.”

Whether he gets a chance to prove his health to the Celtics remains one of the big mysteries as Boston heads into the offseason. Walker’s contract will keep the Celtics from being players in free agency for the next two years, unless Danny Ainge is somehow able to find a trade partner for the veteran point guard. But given his contract, the Celtics would likely have to sweeten any deal with draft picks, young talent, or by taking on another albatross of a contract.

Walker didn’t want to consider that on Tuesday night. While the Celtics were a giant disappointment in 2021, he likes the foundation of the team and hopes to be part of the future.

MORE NEWS: TD Garden Requiring Vaccination Or Negative COVID Test For Bruins, Celtics Games And Concerts

“I do think we have a special group with Jayson [Tatum] and Jaylen [Brown] emerging the way they did this year. They’re two special talents and I think we have a special group,” he said. “We can definitely learn from this season.”