The Boston Globe reported Sunday that according to a Major League source familiar with Drew's background, the star outfielder is scheduled to have a second opinion after concerns arose last week about his shoulder during a team-mandated physical.
The club and Drew's agent, Scott Boras, reached agreement on a five-year contract worth a reported $70 million on Dec. 6. Both sides have maintained that only language issues have kept the deal from being finalized.
According to the paper, it's not known whether the physical issue could cause the deal to fall through or just require revision of the guarantees in the contract.
Another possibility includes the Red Sox shortening the length of the contract or putting more incentives based on Drew's playing time.
The Red Sox are declining comment for now. Drew also declined comment when reached at his Georgia home by the Globe.
Drew's career has been plagued by a number of injuries over his career, including patellar tendinitis in his knee while playing for the Cardinals. He has also been forced to overcome injuries to his back, wrist and shoulder.
Mike Petraglia is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.