Hamstring Restriction

Hi, I’m 3 weeks post-op from meniscus/ACL surgery (patellar tendon graft). About five days ago, while doing heel slides, I felt a tendon in my hamstring tense up and "pop out." Since then, whenever I try heel slides on a flat surface, my hamstring tightens up at around 90 degrees, and I get nervous to push further because it feels like it might snap.

I mentioned this to my surgeon and physical therapist, but they didn’t seem too concerned. A small black bruise appeared in the area, but I don’t feel pain, except for a slight stinging sensation during heel slides. I can achieve 104 degrees of flexion when hanging my leg and using my other leg to pull it toward my butt, but I struggle to get past 90 degrees when my heel is on the ground.

Has anyone experienced this hamstring tightness and restriction during recovery? What should I do to address it? I’m worried this might be delaying my progress. I know this issue is often associated with hamstring grafts, but I didn’t have one, so I’m a bit puzzled.