He felt progressively stronger and crisper each time out.
"Today is probably the best I've felt," Rosenthal said after throwing to Greg Garcia, Jose Martinez and Eric Fryer. "I definitely felt good, felt healthy today. Right now, I'm just going to see how I bounce back and stay on top of things. Hopefully I continue to progress."
Rosenthal will be re-evaluated by the club's medical staff Sunday. If he checks out well, the Cardinals expect to activate him from the DL during their series against the Nationals, which runs from Monday through Wednesday. Sam Tuivailala likely will be optioned to Triple-A Memphis to make room for Rosenthal in the 'pen.
"The ball is jumping out of his hand," Matheny said of Rosenthal. "The secondary pitches look sharp. Everything looked good. It just depends on how he feels."
Lyons commences rehab assignment
Lefty Tyler Lyons threw 58 pitches over 3 1/3 scoreless innings in a Minor League rehab start for Triple-A Memphis on Friday. He scattered three hits, one walk and two strikeouts.
Lyons returned to St. Louis afterward in order to be re-evaluated by the Major League medical staff before the Cardinals determine when and where he'll throw next. Lyons was slowed this spring while finishing his recovery from right knee surgery, which he underwent last November.
"From a knee standpoint, I feel very confident about where I'm at," Lyons said. "I think right now it's just about getting in a little better shape. My legs, in general, are feeling a little weaker than I'd like. It's just a matter of getting in a little better shape and a little better pitching shape. I don't think this is something now where I'm sitting here worrying about how my knee feels."
Lyons can remain on the assignment for up to 30 days, and the Cardinals may maximize that in order to allow him to build up arm strength and prove that he has regained full mobility.
• Stephen Piscotty was out of the lineup Saturday for the second time in three days, this time due to knee soreness. Matheny said Piscotty aggravated his knee sliding into second base on a steal attempt Friday.
Jenifer Langosch has covered the Cardinals for MLB.com since 2012, and previously covered the Pirates from 2007-11. Read her blog, follow her on Twitter, like her Facebook page and listen to her podcast. This story was not subject to the approval of Major League Baseball or its clubs.