Zach Eflin, who is returning from back surgery, said he’ll throw his first bullpen session on Jan. 6.

If all goes well, Eflin could be part of the season-opening rotation, but it’s also possible he’ll start off on the injured list. Eflin re-signed with the Orioles on Sunday after becoming a free agent at season’s end. He’s guaranteed $10 million next season, with a chance to earn up to an additional $5 million if he proves healthy.