The only difference is that no waiver process was needed to secure Byrd's services this time around. He had been temporarily retired, but staying in shape all year in case the right situation presented itself.
"I'm excited," said Byrd. "I think I can be back in shape and help them out in whatever role they need me to help them out in September. Maybe I can get that World Series ring."
The Red Sox have given him that opportunity, though it's unclear when Byrd will be ready to join manager Terry Francona's rotation. Byrd will start out at the team's Spring Training complex in Fort Myers, Fla.
Josh Beckett and Jon Lester have been dominant at the top of the rotation, but the team hasn't been able to fill the void left by Tim Wakefield and Daisuke Matsuzaka, both of whom are on the disabled list.
Brad Penny, John Smoltz and Clay Buchholz have all been inconsistent.
"I am in shape, I have been throwing," said Byrd. "It's not like I haven't picked up a ball. I have been throwing, I've been off a mound twice in the last three days, six times in the last two weeks. There's a difference between pitching in a game and throwing a bullpen. I would need to start out at one or two innings and build up arm strength."
The 38-year-old Byrd has is a career 108-93 with an ERA of 4.38. For the Red Sox last season, he made eight starts, going 4-2 with a 4.78 ERA.
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.