John Smoltz will make his final rehab start for Triple-A Pawtucket on Wednesday. The 30-day clock on his rehab assignment will expire two days later, on June 19th. Yet Smoltz will not make his return to the majors until June 25th, when he comes back against the Nationals.

All of that being the case, it seems fair to ask: what happens to the Red Sox roster between the 19th and 25th? Will the Sox be left, for all intents and purposes, with a 24-man roster?

In short, the answer is no. Until Smoltz pitches in Washington next Thursday, the Sox will not have to make a roster move that undercuts their depth while waiting for Smoltz to make his first start.

At the conclusion of the 30-day rehab assignment, Smoltz does not have to be added to the major-league roster. Unless he incurs a new injury (which would make him eligible for another 30-day rehab assignment), he simply won’t be allowed to pitch in any more minor-league games prior to his return to the majors.

Hypothetically, Smoltz could remain on the disabled list all season after his rehab clock expires. In practice, if a healthy player remained on the D.L. for an excessive period after completing a rehab assignment, another team could complain to Major League Baseball, and the Commissioner’s Office could force the Sox to either activate or release Smoltz.

In this case, however, the Sox will not be abusing the D.L. system, and so no such punitive measures will be required. Instead, Smoltz will officially “return from rehab” on June 19th, and then, presuming that he is healthy and ready, he will be “reinstated from the disabled list” next Thursday against the Nationals. Until he is reinstated from the D.L., Smoltz will not be a member of the 25-man active roster, and so will have some time before their potential move from a seven- to a six-man bullpen.