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6/14/2013 4:40 P.M. ET

Cardinals option Wacha, activate Westbrook

Side by side, Tyler Lyons and Michael Wacha threw their in-between-starts bullpen sessions at Citi Field on Thursday. One day later, the Cardinals decided to option Wacha to Triple-A Memphis in order to clear a roster spot for right-hander Jake Westbrook, whom they activated off the 15-day disabled list ahead of his start on Friday night at Miami.

The Cardinals wanted Lyons and Wacha to throw on Thursday so that the organization could keep both as options for Sunday's start against the Marlins. Though Westbrook will take Lyons' spot in the rotation, it seems Lyons will now be pushed back to start on Sunday.

Following Thursday's 2-1 win over the Mets, Cardinals manager Mike Matheny said that a roster move hadn't yet been finalized and that everyone on the 25-man roster at the time would be traveling to Miami.

"There are a lot of moving parts here," Matheny said on Thursday. "We haven't ruled out anything. We're just trying to take in all the information we can. Time is something we have, and we'll take every minute that we have to make sure we're doing the right thing."

That decision came on Friday, with the Cards optioning their No. 4 prospect, according to MLB.com, back to Memphis. Wacha, who made his Major League debut on May 30, went 1-0 with a 4.58 ERA in three starts with St. Louis.

As for Lyons, the 25-year-old lefty is 2-2 with a 3.51 ERA in four starts since making his big league debut on May 22. After allowing just one run over seven innings in each of his first two outings, Lyons has allowed four earned runs in each of his last two starts, while tossing a combined 11 2/3 frames.

On Thursday, Matheny did not discount the possibility that both Lyons and Wacha would remain on the roster, with one of the two sliding into the bullpen, though that did not come to fruition.

Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.