It's likely he had been experiencing pelvic pain and inflammation all over his lower body. If you've ever been hit in the testicles, you probably felt a sharp pain in the pit of your stomach/bowels area. I would imagine that the that the inflammation that the body initiated after the accident last season caused these problems. These types of conditions tend to be more common in people who had STI's or sometimes vasectomies. With mitch's terrible injury (this is the worst testicle injury I can recall in sports), It's not super surprising that these problems are happening though they are difficult to understand, diagnose and treat. It's entirely possible that pelvic pain and issues continue to affect Mitch not only through his baseball career but in his life after baseball as well.

Tulowitzki is the most similar injury I can recall to what Mitch is dealing with. In 2012 he was DL'ed with a groin strain. When it didn't improve it was discovered he had a sports hernia and had surgery. 2 years later the groin problems returned and it was discovered he had a torn labrum. It's worth noting that Tulo was extremely productive when he played between these procedures but a groin strain ended up being a chronic condition.

It's completely understandable that these additional injuries happened. As long as Mitch had been seeing pelvic floor/core muscle specialists following his injury then it would be tough to blame the Mariners training staff for this. But if they were trying to handle this complicated injury internally then they should absolutely be blamed. World class pelvic floor doctors and urologists don't fully understand this so there's no way a baseball team's training staff could make determinations on Mitch's health.