Photo: Matt Stone/MediaNews Group/Boston Herald

Kemba Walker revealed his frustration due to the setback with the knee injury he suffered in February.

Even though he has put in a lot of work to recover, the superstar of the Boston Celtics is not at his very best yet.

“Yeah, it’s been frustrating. 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,” Walker told reporters, via Darren Hartwell of NBC Sports.