CHICAGO - Twins righthander P.J. Walters could spin Wednesday's outing the following way: If Chicago outfielder Alex Rios had called in sick, Walters might have been talking about a victory after the game.

Walters, however, didn't see a silver lining as his pitching was responsible for the Twins' 6-2 loss to the White Sox at U.S. Cellular Field.

"No," Walters said when asked if he can be satisfied with all but two of his 99 pitches on Wednesday. "Six runs. We lost. Bad day. No way around it."

Two bad pitches to Rios turned into two home runs -- one a grand slam -- and a career-high six RBI. While Rios celebrated his career day, Walters focused on the big picture.

He was called up in May when the Twins' starting rotation was falling apart and propped it up some, going 2-2 with a 5.40 ERA. But a shoulder injury cost him two months.

He returned to the mound Wednesday with less than a month to audition for the right to compete in spring training for a spot in the starting rotation. He has little room for error on the mound and no room for error this month as he auditions for next season.

Stan Schmidt — Associated Press, Star Tribune
Starting pitcher P.J. Walters was pulled from Wednesday's game against the Chicago White Sox during the sixth inning.

Walters was knocked out of the game in the fifth after a walk and Rios' second home run, a blast estimated at 436 feet. Walters gave up six runs on five hits and three walks with four strikeouts.

"I wasn't missing by a whole lot, but enough to be balls," he said. "To me, that's a big part of the game; not so much the homers as the three walks. If I don't walk those three guys ... all three of them score and it turns into a one-run game and maybe it plays out completely different."

Maybe. Maybe not. But his day could have been a lot different if he didn't give up a single and two walks in the first inning before Rios hit a slider an estimated 410 feet to left for a grand slam and a 4-0 Chicago lead. The Twins never recovered from that punch to the gut.

For Twins manager Ron Gardenhire, it was a reminder of how the season has gone. Starting pitchers putting them in an early hole, neutralizing their running game, helping the other pitcher relax and throw strikes. It was more of the same from Twins starters over the past week, as they posted a 5.91 ERA during their six-game road trip.

This is the time of year that Walters needs to separate himself from the other contenders. He doesn't throw hard, so he has to be accurate with his location and use all four of his pitches -- fastball, slider, curve and change up -- to keep hitters guessing.

He did it after the Rios grand slam, retiring eight of nine during the third, fourth and fifth innings before Rios got him again in the fifth inning.

"I thought he had pretty good stuff," Twins catcher Ryan Doumit said. "He got into a nice little groove from the second to the fifth where he was locating his pitches and working quick. I think that's one of his strengths, the pace at which he works. He gets the ball and he goes."

The Twins and Chicago had similar issues this season as both clubs turned to inexperienced starters to help prop up the rotation. Chicago has had rookies Jose Quintana, Dylan Axelrod and, on Monday, Hector Santiago, step up.

Scott Diamond has been a revelation for the Twins. Samuel Deduno's command has improved. Cole De Vries has been crafty at times. Walters and Liam Hendricks need to finish strong to improve their position for next season.

"These guys that are trying to win a spot in this rotation, or get a look [next spring], they need to start getting deep into the games for us, Gardenhire said. "I think we got about 16 innings out of our starters in this series, and you need more than that."