"There have been a few games where he's had a few mistakes, but more at third than short, and I told him he hadn't played on the left side of the field all year," Molitor said. "I think little by little he's gaining more confidence. We're trying to give him an opportunity, obviously."
Polanco's bat has helped keep him in the lineup, as he's hitting .347/.355/.440 with three doubles and two triples in 18 games since getting called up on July 29. He went 1-for-4 on Thursday, and has a hit in 18 of his 20 games since his callup.
"I just try to be as simple as possible at the plate," Polanco said. "I don't try to do too much. Just try to get a pitch to hit."
Polanco, who appeared at shortstop in 339 games in the Minors, also said he feels like he's starting to settle in defensively. He's worked hard to improve his arm strength over the years.
"I feel like I've been doing better than a couple years ago," Polanco said. "My confidence is high."
With Polanco getting regular starts at shortstop, it's relegated shortstop Eduardo Escobar to more of a backup role. Molitor said he's had to sit down with Escobar a few times to explain to him the situation that they want to see what they have in the 23-year-old Polanco.
"Anybody who is accustomed to playing regularly and gets their time cut into, I think you have to be concerned about that," Molitor said. "Right now, we've got a kid up here playing pretty well. It's hard for him to look at the large picture of what we're trying to do to get a look at our talent pool here. So I have to try to check in with him and keep him positive. That's part of the chemistry of the team."
• Miguel Sano, who missed the previous three games with a sore right elbow, returned to the lineup against the Royals and started at third base. It marked Sano's first start at third since Aug. 7.
• Joe Mauer also returned to the lineup after missing Wednesday's game against the Braves with sore quads. The Twins will continue to monitor Mauer, but the injury isn't considered serious.
• The Twins are expected to announce they renewed their player-development contract with Rochester. The contract was set to expire after this season.
Rhett Bollinger has covered the Twins for MLB.com since 2011. Read his blog, Bollinger Beat, follow him on Twitter @RhettBollinger and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.