"It felt good being here, but I didn't have my best stuff," Lohse said. "I had some issues come up and I had to battle through it. I tried to give them as many innings as I could, but I didn't have my best fastball."
Rangers starters are now 0-6 with a 10.45 ERA in their last eight games with one more to go before the badly needed All-Star break.
"Obviously a challenge," Rangers manager Jeff Banister said. "We go as our starters go. When we get a quality start, we have proven all year, our offense will give us the opportunity to win baseball games."
Lohse was making his 417th Major League start in a career that began in 2001 with the Twins. That's the third most among active pitchers, but the Rangers know they are not getting the same pitcher who was a 16-game winner with the Cardinals in 2012 and seventh in the Cy Young Award voting.
Lohse was 5-13 with a 5.85 ERA in 37 games for the Brewers last season and 3-5 with a 5.06 ERA in 10 starts with Triple-A Round Rock after being unable to find a big league job as a free agent.
The Rangers are just hoping the 37-year-old right-hander has enough left to plug a hole in the rotation until Yu Darvish and Derek Holland return from the disabled list, or they pull off a trade for a starter closer to his prime.
"I thought he mixed well," Banister said. "He tried to use soft [pitches] away and use his sinker. But we were behind in counts and ran the pitch count up. He went out and pitched and gave us all he had. There is still some stuff there."
Lohse pitched a scoreless first inning, but ran into trouble in the second with a one-out walk to Kennys Vargas. Eddie Rosario followed with a double and Juan Centeno lined a single to give the Twins a 2-0 lead.
The Rangers were able to fight back against Twins starter Ricky Nolasco and give Lohse a 3-2 lead into the fourth. But the Twins struck back themselves on an RBI double by Danny Santana and a two-run home run from Eduardo Nunez.
Lohse went back out for the fifth, but an early visit from trainer Kevin Harmon and pitching coach Doug Brocail was visible evidence he was struggling physically. Lohse got through the inning, but gave up a home run to Rosario that made it 6-3.
"I didn't want to put the bullpen in there for nine innings," Lohse said. "Not making excuses. … I took the ball and battled with what I had. I just didn't have my best stuff."
T.R. Sullivan has covered the Rangers since 1989, and for MLB.com since 2006. Follow him on Twitter @Sullivan_Ranger and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.