Amid all the time he has put in rehab, Kemba Walker's knee is still not in tiptop form. And this has immensely frustrated the Boston Celtics star guard.

In a Zoom call with reporters on Thursday, Walker gave an update on the status of his knee. Walker shared that he has put it all the work, but his knee still isn't at 100 percent.

“Yeah, it's been frustrating,” Walker said, per Darren Hartwell of NBC Sports. “I've been going through this pretty much most of the season, even before this bubble stuff. So, it's been something that's been nagging for a little bit now.

“Unfortunately it's still bothering me even after I’ve put in a lot of work and did the necessary things to try to get it right.”

In Sunday's scrimmage against the Phoenix Suns, Walker logged in just nine minutes of action. He chipped in six points and was his old aggressive self. However, his latest interview perhaps reveals the real status of his knee. It's been nagging Walker since January and even caused him to miss 10 games. Even the four-month hiatus wasn't enough for him to fully recover.

In the Celtics' seeding round opener against the Milwaukee Bucks on Friday, Walker will be limited to 15-20 minutes. From the looks of it, head coach Brad Stevens is not risking anything. The Celtics are already in the playoffs and some even believe they have a chance to win it this year. But to do so, they need a healthy Walker to lead them.