PHILADELPHIA -- The Red Sox placed left-hander Christopher Johnson on the 10-day disabled list with a left shoulder impingement on Thursday and selected the contract of right-hander Austin Maddox from Triple-A Pawtucket.
Johnson exited Wednesday's start vs. the Phillies after 2 2/3 innings, though he said after Boston's 7-3 win that he felt something was off during his warmup in the bullpen. The southpaw has a 4.29 ERA in four starts, with 17 strikeouts in 21 innings.
Johnson, who is ranked the club's No. 11 prospect by MLBPipeline.com, was headed to Boston on Thursday and was set to undergo an examination on Friday, said manager John Farrell.
Right-hander Hector Velazquez will take Johnson's spot in the rotation and start Monday at Kansas City. Velazquez, who was called up Wednesday, took over for Johnson and threw 3 1/3 innings of scoreless relief for his first Major League win.
Meanwhile, Maddox will add another arm for the Red Sox's bullpen. Maddox has so far posted an excellent season between Double-A Portland and Pawtucket. In 27 innings, the 26-year-old has registered a 1.33 ERA and a 1.037 WHIP in 18 games.
"I've been staying true to myself. Staying within myself, and trusting myself and attacking hitters," Maddox said of his 2017 season.
The move might be bittersweet for the two pitchers, as they were teammates at the University of Florida before being selected in the 2012 Draft by the Red Sox. Johnson was taken in the first round, while Maddox heard his name called in the third round.
To make room for Maddox on the 40-man roster, Boston transferred left-hander Roenis Elias to the 60-day DL.