SARASOTA, Fla. -- The Red Sox were already preparing for the possibility of setup man Tyler Thornburg opening the season on the disabled list due to the right arm fatigue that slowed his Spring Training.
But another setback has turned it into an inevitability.
Thornburg was scratched from his scheduled outing against the Orioles on Monday due to upper right trapezius spasm. It would have been Thornburg's first appearance in a Grapefruit League game since March 1 and his third overall.
"Yeah, it's hard to say right now he'd have enough frequency of outings and pitch count to build up and to be ready by next Monday," said Red Sox manager John Farrell. "We haven't made that determination yet. Tomorrow is going to hopefully give us more information on what we're actually dealing with here. What the root cause to the spasm is, that I don't know at this point."
President of baseball operations Dave Dombrowski characterized it as "likely" that Thornburg will start the season on the 10-day disabled list.
When the Red Sox acquired Thornburg from the Brewers in December, the plan was that he would be the team's main setup man in the eighth inning.
Even before Monday's injury, Farrell had said in recent days that Thornburg would start the season in lower-leverage outings.
Joe Kelly will probably begin the season pitching the eighth inning, but Richard Hembree and Matt Barnes could also get opportunities to set up Craig Kimbrel.
At this point, Dombrowski hopes the injury will be short term, and he doesn't plan on acquiring another reliever before Opening Day.
"Well, I think we're fine," said Dombrowski. "Some guys have to step up is what it comes down to. You go through these type of things in any particular year. I've gone through it every year in my career. We like guys in our bullpen. Joe Kelly, Matt Barnes -- those guys are going to have to step up. Heath Hembree. Robbie Ross. We're just in a situation that they'll have to pick up the pieces for now."
With Thornburg out of the Opening Day mix, the Red Sox likely have two roster spots up for grabs in the bullpen instead of one.
Righties Kimbrel, Kelly, Barnes and Hembree and lefty Ross are the five relievers who are certain to make the team.
Without Thornburg, the Red Sox could break camp with three lefty relievers, including Fernando Abad and Robby Scott. Five non-roster pitchers also remain in the mix for a spot: lefty Edgar Olmos and righties Jamie Callahan, Chandler Shepherd, Ben Taylor and Austin Maddox.
"There are about three or four guys that we think are on the verge of pitching at the big league level," said Dombrowski. "Guys like Shepherd and Callahan, Maddox and Taylor. People don't know them but they're here for a reason, and we still like them. We think they're real close."