Ron Gardenhire popped out of his office on Tuesday afternoon and pointed toward a couple of players in the clubhouse. Danny Valencia flinched before realizing he wasn't in the line of fire.

Gardenhire called two others in and explained that they would be playing out of position. Then Michael Cuddyer started jogging toward the field, realized he needed his outfield glove instead of his first-base mitt because of all of the Twins' injuries and U-turned to his locker.

Rain wiped out the Twins' game with the White Sox on Tuesday night. Before the monsoon, the home team's clubhouse felt like a morning late in March, when spring training ceases to be frivolous, the real big-leaguers start eating up at-bats and crestfallen players shuttle across the parking lot to the minor league clubhouse.

The Twins are about to execute a midseason lineup change, with Joe Mauer, Joe Nathan, Jim Thome, Denard Span, Tsuyoshi Nishioka, Glen Perkins and Jason Kubel jumping over the boards. Soon, Gardenhire will face his toughest decisions of the year.

With Nishioka taking over at shortstop and Alexi Casilla earning the second base job, Luke Hughes becomes direct competition for Valencia at third.

When Span and Kubel return to the outfield, Ben Revere becomes competition for Delmon Young in left.

This, of course, presumes a sudden epidemic of good health, which would be like expecting LeBron James to join Up with People.

On Tuesday afternoon, Justin Morneau sounded resigned to a trip to the disabled list, a move made official later in the day. With Morneau sidelined, Cuddyer will often play first base, meaning Revere, Young, Span, Kubel and Thome could divide four positions five ways, meaning plenty of at-bats for all of them.

If this team ever becomes completely healthy, Gardenhire will be forced to make touchy and important choices between incumbents who seem too comfortable and prospects who have acted as franchise defibrillators.

Young and Valencia became two of the Twins' most valuable players in 2010, Young by leading the team in RBI and Valencia by suturing the franchise's festering wound at third base.

This season, both have squandered the opportunity to make themselves franchise fixtures. Young wasted the first two months of the season. Valencia has produced RBI but too few quality at-bats.

Last year, Young's combined on-base and slugging percentage was .826. This year, it's .588. Valencia's OPS has slipped from .799 last year to .611 this year.

Gardenhire prodded Valencia by benching him for consecutive games on the last road trip, and Hughes has outplayed him of late. Benching or demoting Valencia might serve two purposes, rewarding the hotter player and jolting the slumping incumbent.

Gardenhire faces a tougher decision in left should all of his outfielders ever become healthy at the same time. Young is 8-for-16 with a home run on the homestand, and over the course of his career, his most productive months have been June and July. He could be ready to reprise his role as the Twins' most important hitter in 2010.

If forced to make the choice, should Gardenhire invest faith in Young, or should he reward Revere, who lacks Young's power but vastly outperforms him as a fielder and baserunner, giving Gardenhire the kind of energetic player he craves?

I asked Gardenhire how difficult his decisions will be, and he refused to isolate those positions.

"All the way up and down, not just left field and third base," he said. "We have a lot of tough decisions to make about who goes and who stays."

Despite Young's pathetic first two months, the Twins owe it to themselves to play him as long as he displays a pulse, so they can either reap the rewards of one of his typical midsummer surges or market him for a trade. Revere can back up all three outfielders, pinch hit and pinch run.

The decision at third is simpler. Valencia doesn't possess Young's power potential or trade value. Gardenhire should favor the hotter player, and that is Hughes.

Jim Souhan can be heard Sundays from 10 a.m.-noon on AM-1500 KSTP. •