Lefty reliever Tim Collins is slotted to pitch again tonight when the Royals play the Chicago Cubs in concluding a day/night doubleheader that commences this afternoon against Milwaukee.

Collins could really use a dominant performance to quell growing concerns after after enduring another rocky outing in Tuesday’s 11-6 victory over Seattle.

Two booming homers by the Mariners push the grim math on Collins to 11 runs and 13 hits in seven spring innings.

Manager Ned Yost continues to say Collins needs nothing more than a few tweaks to regain his expected form, but the regular season is now just five days away.

“He’ll be all right,” Yost said. “It’s not really an issue right now. I mean, it’s an issue because we’re one week away from starting the season, but we don’t have any concern that he’s not going to be ready.”

Things change quickly, though.

There was a point this spring when first Luke Hochevar and then Bruce Chen appeared positioned as favorites for the final spot in the rotation. Now, both are in the bullpen after losing out to Luis Mendoza.

Collins has options remaining, and if his struggles continue — he’s slotted for two more spring appearances — it’s not hard to imagine him being sent to Class AAA Omaha to work out whatever mechanical tweaks are required.

Francisley Bueno and Donnie Joseph provide the Royals with viable alternatives to the need for a lefty reliever if club officials believe Collins requires a quick remedial tour in the minors.

It could all be moot by Friday if, between now and then, Collins again displays the form that made him a durable and valuable member of last year’s bullpen.

Either Bueno or Joseph could also make the final roster alongside Collins. Both are in contention for what, barring a Collins demotion, looms as the last available spot in the bullpen.

The other candidates are right-handers J.C. Gutierrez, Dan Wheeler and Louis Coleman. All five are scheduled to pitch at some point in today’s games.

Mendoza will start the afternoon game against the Brewers in Maryvale. Here’s the lineup:

CF Jarrod Dyson, SS Alcides Escobar, 1B Xavier Nady, 3B Miguel Tejada, LF Irving Falu, C George Kottaras, RF Paulo Orlando, 2B Rey Navarro and Mendoza. The DH won’t be used.

Nady’s presence in the lineup suggests he signed a new minor-league deal with the Royals after being released following Monday’s victory over the Dodgers.

James Shields is slotted for tonight’s game against the Cubs, which can be seen at 8:05 p.m. Central time on Fox Sports Kansas City.