The Boston Red Sox’s bullpen might be down a man to start the season.

Reliever Tyler Thornburg, who was acquired from the Milwaukee Brewers over the offseason, was scratched Monday after he was expected to make an appearance for the Red Sox in their spring training game against the Baltimore Orioles.

The right-hander suffered a spasm in his upper right trapezius, and Red Sox manager John Farrell and president of baseball operations Dave Dombrowski both acknowledged that Thornburg likely will begin the season on the disabled list.

“During the pregame throwing program, he felt like there was some spasm that was taking place in the trap area,” Farrell told reporters, per WEEI.com. “It wasn’t shoulder-related. So we scratched him from the outing here (Monday). Sent him back early to gain some treatment, and he’s set to have further testing (Tuesday).

“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 (for Opening Day). We haven’t made that determination yet. (Tuesday) is going to hopefully give us more information on what we’re actually dealing with here. What the root cause to a spasm is, that I don’t know at this point.”

Thornburg already has dealt with shoulder soreness this spring, limiting him to just two appearances, the most recent of which came March 1. The Red Sox acquired Thornburg with the hope he’d be able to handle the team’s eighth-inning duties ahead of closer Craig Kimbrel, but Boston now could be forced to rely on the likes of Joe Kelly, Matt Barnes, Heath Hembree and/or Robbie Ross Jr. in that role.

Thornburg is coming off a season in which he went 8-5 with a 2.15 ERA in 67 appearances spanning 67 innings. The 28-year-old saved 13 games and posted a 0.94 WHIP while striking out 12.1 batters per nine frames.

Thumbnail photo via Kim Klement/USA TODAY Sports Images