The Reds have admitted that they are concerned about Aroldis Chapman's recent dip in velocity.

Chapman, who routinely throws over 100 miles per hour, struggled on Monday night against the Pirates. He averaged a season-low 94.4 mph on his fastball and threw just seven of his 23 pitches for strikes.

"His velocity was down," Dusty Baker said. "He didn't have any pain. He might be a little tired. We might have to rest him for a while here."

Chapman is tied for the National League lead with 35 saves this season. He is 5-5 with a 1.60 ERA and 119 strikeouts.