"I noticed it getting sore towards the last few innings there last time, and it was sore all week," Morrow said after the game. "Loose but sore. It just wasn't ready today. It wasn't explosive. The ball wasn't coming out."
Morrow lasted just two innings, and he clearly wasn't himself on the mound. He allowed four runs -- two earned -- on four hits while striking out two in the start, his 10th of the season. With the score tied at 4, Morrow didn't come out to begin the third inning.
The righty threw 47 pitches, but just three were above 90 mph, compared to his normal mid-90s velocity. His drop in velocity was related to the forearm soreness, as he couldn't get the muscle to loosen up.
"It's a muscle strain, so it's not firing like it should," Morrow said. "I couldn't let it go. Maybe on the slider, it was probably the worst, just because you have to get on top of that ball a little bit more."
Morrow was not in line for a decision after his abbreviated outing, so he remained 2-3 on the season with a 5.63 ERA. The No. 2 starter missed time earlier in the year with soreness in his upper back and neck, but he is hopeful that this injury won't cause him to miss any time.
"Rest and treatment and everything -- I hope to make that start," Morrow said.
Evan Peaslee is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.