Here is what is going on: The Twins called it "stress reaction" here is what that means (other than the psychological meaning) : Medial tibial stress syndrome (MTSS) is an overuse injury or repetitive-stress injury of the shin area. Various stress reactions of the tibia and surrounding musculature occur when the body is unable to heal properly in response to repetitive muscle contractions and tibial strain. Fouled ball cannot cause it. It is an acute singular event. So he either has a stress reaction because of the continual use (btw, a synonym of a stress reaction is stress fracture, but they really don't want to give the message that he has a broken leg), or he has an acute bruise or even a fracture from that singular event. If it were a bruise, the recommended treatment is no activity until the swelling goes away (usually a week or so) and slowly but steadily build up. I think that, based on what they are saying, this looks like his time table or treatment. On the other hand, it does not respond, which makes me think that it might be worse. A fracture treatment is 6-8 weeks of rest then slow but steady build up. He has been off for a month, so we are looking for another month or so before he will be playing. I think that the hope was that he could swing (without putting any weight on his chin?) and be a DH, but I do not see that happening this season. As far as the future goes, he is this team's third baseman of the present and future. Yes he is not skinny, but he has a strong muscular base to hold his weight and his glove is better than Koskie's at that development level at third, and will improve. There will be some thought to turn him on the other side of the diamond in 2018, but Rooker's arrival as Mauer's replacement will put an end on this thought.