On August 14, American baseball infielder and outfielder Jeff McNeil injured his left hamstring in a game against the Braves. The injury happened when McNeil sprinted towards the first base in an attempt to make an infield single.  An MRI–which would not typically be obtained for this type of injury–revealed a mild hamstring strain, an injury for which he missed 12 games in May and June. It’s safe to play with a muscle strain. People usually return when they are comfortable enough to be effective. They complete healing over a full year.