Stretching and its effect on the muscle tendon in footballers

Stretching is a commonly used tool in pre-match preparation as well as in rehabilitation. There are different stretching techniques, which might benefit one or the other purpose. A good example here would be the utilization of static vs. dynamic stretching in a pre-match warm-up or to increase range of motion in a flexibility session.

While the research mainly focused on the muscle (and even more on its force producing capability), it seems relevant to ask what actually happens during stretching and which part of the muscle-tendon unit (which includes the tendon, the connective tissue or myotendinous junction (MTJ) = the part in which the “muscle turns into the tendon (1)” and the muscles) is stretched? Anecdotally it was believed that stretching would alter tendon length, which would therefore cause instability to a given joint and further increase injury risk?