Given the sentence "A third baseman is chasing a base runner back to second base." is it true that "The third baseman fell and broke his leg when he was trying to get a runner out at second."?
Let's be accurate as possible and think first.
it is not possible to tell
If a third basemen is chasing a runner is does not follow that he fell and broke his leg.

Most baseball plays do not involve injuries.

A player chasing a runner back to second is not necessarily trying to get a runner out.

The goal of chasing a base runner can be simply to get the runner to return to second base.

.

The answer: it is not possible to tell