Atlanta Braves starter Reynaldo Lopez was removed from Tuesday night's 12-0 win against the host Washington Nationals because of right shoulder tightness.
Lopez made it through just one scoreless inning, allowing a double and hitting a batter while striking out one. He threw 25 pitches, 16 for strikes. His fastball velocity -- usually 96 mph -- was down to the 89-94 mph range.
He and three relievers limited the Nationals -- losers of seven of their last 10 games -- to three hits.
Lopez will undergo an MRI on Wednesday.
"We are getting him looked at and we'll determine something tomorrow," Braves manager Brian Snitker said. "He's checking out OK. I talked to him. I just saw the velocities were not good, and then when I talked to him after and kind of made him fess up and he wanted to keep going. But when he stepped on it he didn't feel great."
Lopez said he was surprised.
"To be honest I really didn't know what was happening," he said via an interpreter. "I felt like that first pitch went out and I thought it was 95 mph and it I took up and it was 89 mph. So that took me by surprise. That was just something I wasn't expecting. I was definitely relieved when everything came back normal and good. I think it is right we are just being overly cautious."
Lopez, an All-Star right-hander, was making his fourth start since a monthlong stint on the injured list due to tightness in his right forearm.
He took an 8-5 record and a 2.04 ERA into Tuesday night's start.
Information from The Associated Press was used in this report.