"Tyler has had a strong season," manager Mike Matheny said. "I like where he is right now and what he brings to our club. Here is a guy who has been consistent through this season and gives us a good shot. We've seen a couple real nice starts from him, and hopefully we get a few more."
The Cardinals have not committed to keeping Lyons in the rotation for the duration of Westbrook's absence as the veteran deals with a lower back strain, though Matheny noted that it was doubtful that the club would use an off-day next Thursday to skip that spot in the rotation the next time through.
Changing Lyons' role also puts a lefty back in the Cardinals' rotation just as the team prepares to face two division opponents who have been average against lefties this season. The Reds are 22-21 against left-handed starters, compared to 51-34 versus righties. Pittsburgh, despite being 23 games over .500, is 12-12 against lefties. If the Cardinals continue with this five-man rotation, Lyons would face the Pirates in back-to-back starts after Monday.
The Cards are 2-5 in Lyon's seven starts this season. He has posted a 5.35 ERA as a starter, and opponents have hit him at a .257 clip.
With Lyons needed in the rotation, the Cardinals have filled his bullpen spot with rookie Carlos Martinez. Martinez was added to the 25-man roster on Friday, the day he was scheduled to start for Triple-A Memphis. Matheny said that Martinez won't be designated solely as a long reliever, though he is stretched out if needed to pitch multiple innings.
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.