Rangers right-hander Miles Mikolas will make his first Major League start against the Orioles on Wednesday in the third game of a four-game set at Camden Yards. Mikolas was called up on Tuesday to take the rotation spot of Joe Saunders, who was designated for assignment after allowing seven runs in five innings on Monday.
Mikolas was acquired from the Padres this winter for first baseman Chris McGuinness, and has been a reliever since 2009, posting a 3.44 ERA in 27 appearances for the Padres over the past two seasons.
He last pitched on Thursday for Triple-A Round Rock, so the Rangers inserted him on Wednesday while Nick Tepesch was pushed back to Friday behind Yu Darvish.
"Mikolas was due to pitch soon," manager Ron Washington said. "We didn't want him sitting around until Saunders' spot comes up again."
Mikolas did not make the team in Spring Training while dealing with an elbow problem, and he started the season on the disabled list. He was activated on April 1 and assigned to Triple-A Round Rock, where he was 2-0 with a 2.25 ERA in 10 appearances before being moved to the rotation.
In six starts at Round Rock, Mikolas was 3-1 with a 3.58 ERA. Overall, he has walked three and fanned 38 in 44 2/3 innings. He was with the Rangers from May 14-17 but did not pitch.
"He's adjusted to the job description pretty quickly," said pitching coach Mike Maddux. "For him to go out there and go through a lineup multiple times, I guess he's made a pretty quick adjustment. He's added a slider to his repertoire. He has a changeup.
"In Spring Training, we didn't get to see him much. I look forward to seeing him. I'm curious to see him throw. He has a heavy fastball, and I remember him having a pretty good two-seamer from the limited look we had at him."
Mikolas will take on Baltimore's Chris Tillman, who has bounced back from a rough stretch in May to post a 1.61 ERA over his last four starts. In his most recent outing against the Rays, Tillman allowed one run in eight innings, his third straight effort of at least seven frames.
The last team to rattle Tillman was the Rangers on June 5, when Tillman recorded just three outs while giving up five runs.
He will seek support from an Orioles' offense that is hitting home runs in droves, setting a club record with 46 long balls in June. They entered Tuesday second in baseball with 100 for the season, and hit four in eight innings on Monday plus three more Tuesday.
In June, 62 percent of the O's runs came on homers.
"You'd love to be a power-laden, fast, good defensive team and you can hit and run, you can manufacture, nobody strikes out but they hit home runs," manager Buck Showalter said. "You'd like to have all those things, but I don't even think the '27 Yankees had that. But you strive for it.
"You're always trying to play to your club's strengths and that's one of ours, but we all know that really good pitchers don't give up many of those. When pitching's on top of its game and hitting's on top of its game, pitching wins."
Rangers: Pena trying to get hot
Carlos Pena, a left-handed hitter, was out of the lineup on Tuesday with a left-hander on the mound for the Orioles. He will be back at first base on Wednesday night to face Tillman.
The Rangers have been using Pena in the No. 3 spot in the lineup even though he is 3-for-26 (.115) in seven games since being called up from Triple-A Round Rock. He is 1-for-8 with runners in scoring position.
"He is still trying to figure it out," Washington said. "I know he is going to make the plays around the bag but he is still trying to figure it out on the offensive side. We're being patient."
Because of all the injuries, Washington has been scrambling to put a lineup together every night. On Tuesday, Robinson Chirinos was batting fifth for the first time this season and utility infielder Adam Rosales started at designated hitter for only the third time in his career.
"You just have to be patient when you are dealing with a lot of inexperience," Washington said. "As long as they're not getting down on themselves, it's good. They are showing me they are not down. They are playing hard."
Orioles: Gausman to pitch in Minors before potential Sunday start
Right-hander Kevin Gausman will pitch for Class A Short-Season Aberdeen on Wednesday and is a candidate to start Sunday's game in Boston for the Orioles.
Gausman was called up Friday to pitch in a doubleheader against the Rays, but he was then optioned back to the Minors to complete an optional 10-day assignment.
"We thought it was more important that he pitch on his fifth day this time and more important that he got a good workday, which he got yesterday," Showalter said Tuesday. "Off today and then start tomorrow, and then kind of shorten that up and make him available for Sunday."
If Gausman does not start on Sunday, T.J. McFarland -- who made his second career start Tuesday -- is another option.
"Hopefully Mac pitches real well tonight and we have a good problem, but we have to be prepared to go either way," Showalter said.
Gausman, who was eligible to be recalled from the Minors as early as Tuesday, has gone 3-2 with a 3.86 ERA in five starts for the Orioles.
• Mikolas will be the 24th pitcher used by the Rangers this season. That ties the Yankees and the Angels for the most by any Major League team.
• Rangers pitchers had a 4.97 ERA in June, highest in the American League, It was the highest by Rangers pitchers in any single month since a 5.07 ERA in September of 2009.
Aaron Leibowitz is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.