Scioscia said afterward that Middleton experienced a "zinger" that subsided quickly.
"As quickly as it came on, it went away," Scioscia said. "He was evaluated last night by Dr. Yoon, everything checks out. Just a day to day thing. When he's feeling good, he can get back on the mound and get ready to pitch."
Middleton played catch on Friday and will likely throw a bullpen session before being cleared to return to action. He has been a key cog in the Angels' bullpen since making his Major League debut in May, logging a 4.47 ERA over 50 1/3 innings this year.
• Left-hander Andrew Heaney (shoulder impingement) has not thrown since playing catch on Tuesday. Scioscia said Heaney received medication and is "making progress."
"He's taking some medicine, so you want to give that a chance to work," Scioscia said. "Everything from the MRI looks like it's in place, so it's really just going to be when the discomfort is gone and when he's ready to pitch again."
The Angels skipped Heaney's turn against the Rangers on Friday, with right-handed reliever Bud Norris starting in his place.
• The Angels sent right-hander Elvin Rodriguez to the Tigers on Friday to complete their Aug. 31 trade for Justin Upton. Rodriguez, 19, was ranked the Angels' No. 22 prospect by MLBPipeline.com. He posted a 2.50 ERA in 11 starts with Rookie-level Orem and finished the season at Class A Burlington.
• The Angels sent over 18,000 pounds of supplies to Houston to aid victims of the devastation caused by Hurricane Harvey. Infielder Cliff Pennington, a native of Corpus Christi and a resident of Houston, led the effort in conjunction with the Second Harvest Food Bank, collecting donations from fans, front-office personnel and players.
A truck carrying the provisions departed Southern California on Friday morning and was en route to First Baptist Church in Houston, where Pennington attends services in the offseason.
Maria Guardado covers the Angels for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.