The reason the Red Sox haven't held a press conference yet to announce the signing of prized slugger J.D. Martinez is because some contract language is still being worked out as a result of findings from the physical, a source told There are no concerns about Martinez's ability to play at full strength in 2018. The physical did reveal a potential medical issue that could crop up down the road, and the Red Sox and Martinez are simply trying to protect themselves in case that occurs. The sides have worked through the situation cooperatively and professionally, the source added. The expectation is that the deal will still be completed and Martinez will join the Red Sox, but no timetable has been provided for how long it will take to finalize the added language to the contract. The Red Sox ran into similar situations that delayed signings with free agent J.D. Drew prior to the 2007 season and Mike Napoli in the winter before the '13 season. Both situations resolved themselves. Martinez had a sprained Lisfranc ligament in his right foot last year and a right elbow injury in 2016. It is unknown what the precise medical issue is that has delayed the formalization of the much-anticipated union between the Red Sox and Martinez.