Can Tendinitis cause muscle strains, etc

I believe I have tendinitis in the tendon behind my knee on the left side. If any part of my legs ever get sore it’s always that part. I’m thinking because it’s sore, I might run a certain way and unconciously put more stress on it than usually. Because i’ve injured the hamstring on that leg 3 times. (Fall 99, winter 2000, summer 2002) The 1st time being the most serious. When it was injured the 1st time, I was doing some 150’s. Got injured on the last one. Everytime after that it’s been injured during acceleration work. This past Thur. I got through my 1st speed workout in a LONG time with out hurting it. And it was an acceleration work out.
Is tendinitis the cause. Or did I just hurt my hamstring.