Judging by the fact that he's had a chronic knee issue, has been rest days throughout his career, and sustained this injury as a direct result of from a lateral side hit, thereby bending the inside (medial) side of his knee inward its likely that he's sustained a MCL with meniscus damage, which could require microfracture surgery or removal of the meniscus making for more 'bone on bone' rubbing which will increase swelling and require even more rest days. You have a guy whose knee was a ticking time bomb.