Nolasco, 31, has pitched to a 5-7 record and a 5.90 ERA in his first 18 starts for the Twins this season.
"He doesn't think it's going to be something will keep him out a long time," Twins assistant general manager Rob Antony said. "Our doctors were pleased everything looked structurally good. Hopefully it won't be a long process to get him right again and get that stiffness out of there."
Nolasco, who joined the club on a four-year, $49 million deal in the offseason, has dealt with the injury off and on this season, but he didn't tell the training staff about his elbow until Monday. He lasted a season-worst two innings on Sunday, giving up six runs.
"When he was asked why he didn't come forward, he said he didn't want to be that guy who signed a big deal and went immediately on the DL," Antony said. "He said if it would've hurt he probably would've, but it was just stiffness and trouble getting loose."
Herrmann batted .122 in 41 at-bats for the Twins earlier this season, and he's a .176 career hitter in 81 games in the big leagues. Herrmann was hitting .314 with a .383 on-base percentage for Rochester, though, and he had 15 extra-base hits in his first 33 games at Triple-A this season.
Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger. This story was not subject to the approval of Major League Baseball or its clubs.