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6/18/2014 12:45 P.M. ET

Siegrist's rehab delayed by nerve issue in shoulder

ST. LOUIS -- Instead of throwing his scheduled bullpen session Wednesday and then departing for a Minor League rehab assignment, left-hander Kevin Siegrist is on hold, now waiting for tightness in his shoulder to pass.

Siegrist went on the disabled list with a left forearm strain on May 24. That injury, Siegrist reiterated on Wednesday, is no longer a bother.

The Cardinals believe this current discomfort is related to a nerve issue. Siegrist compared the discomfort to that which he felt the second week of Spring Training, when arm soreness forced him to skip a side session. That was hardly a setback, though, as Siegrist returned to the mound later that week and had no other arm problems all spring. He hopes this is the same.

"Everything else is fine," Siegrist added. "I think taking time off for my forearm de-conditioned my arm."

The tentative plan is to have Siegrist throw his next side session on Friday, though that is dependent upon how the next two days go. Whether he will then head out on a rehab assignment immediately has not yet been determined.

"We'll just have to keep watching and listening to the medical staff and figure out what the game plan is going to be," manager Mike Matheny said. "We'll go as slow as we need to."

Wainwright set to make next start

ST. LOUIS -- Adam Wainwright declared himself ready to start, as scheduled, on Saturday after throwing 35-40 pitches in a morning bullpen session at Busch Stadium on Wednesday.

Wainwright, who skipped his start Monday due to lingering tendinitis in his right elbow, increased the intensity of Wednesday's session to give his arm an ample test. The Cardinals were prepared to have him miss another outing had his elbow not responded as hoped to the recent rest.

"I'm smiling right now," Wainwright said, minutes after throwing. "The feeling that I had last game was incredibly annoying, incredibly bothersome. I don't have that anymore, so I'm smiling. I think now we take steps to make sure we maintain things and do a little more work in the training room for the next couple of weeks probably to make sure it doesn't come back. After that, we're smooth sailing."

Wainwright pitched through elbow discomfort for several weeks, though it became a particular nuisance in his start against the Rays on June 10. That led to an early return flight to St. Louis for an MRI, which confirmed that he was not dealing with a ligament issue. Wainwright underwent Tommy John surgery three seasons ago.

The Cardinals started Carlos Martinez in Wainwright's place on Monday but are hopeful that their ace can manage this issue without having to be unplugged again later this season. The right-hander currently leads the National League with nine wins. He was also the Majors' first pitcher to eclipse 100 innings pitched, doing so in his last outing.

"We're going to keep talking to him and hopefully he continues to do the right thing and let us know how he is feeling so we can get ahead of [any other problems]," manager Mike Matheny said. "The reason we take this little break is to hope it won't return. But we have to keep watching it. If we need to take more time, we take more time. That's all there is to it."

Cards to welcome PLAY Campaign to Busch

ST. LOUIS -- The 2014 National PLAY Campaign will be visiting Busch Stadium on Thursday, during which the program will promote its mission of encouraging children to engage in an active lifestyle. The group is making a similar stop at Nationals Park over the weekend.

PLAY (Promoting a Lifetime of Activity for Youth) will be holding events at all 30 Major League Baseball stadiums before the end of the season. Their recent partnership with The Professional Baseball Athletic Trainers Society (PBATS) will also ensure that children with disabilities are able to participate in this year's events.

The Arc, a nonprofit organization that aims to promote and protect the human rights of people with intellectual and developmental disabilities, will send children from its area chapters to the ballpark for the event.

Former Cardinals head athletic trainer Gene Gieselmann (1969-97) is among the founding members of PBATS. Thursday's event at Busch Stadium, which will include several instructional stations, is expected to last about two hours.

Worth noting

• Tyler Lyons (left shoulder strain) remains in a holding pattern in St. Louis, as the Cardinals determine whether to have him make another Minor League rehab appearance this week or take him off the disabled list. If the organization does the latter, then the decision becomes where to assign Lyons. He last pitched on Saturday, going 2 2/3 innings in a rehab appearance with Triple-A Memphis.

"He's real close," Matheny said, when asked about Lyons' timetable. "It's about time that he's to get out and pitch on a consistent basis. We have to wait to see how things play out here."

• The Cardinals haven't said how much longer they will stick with a four-man bench, but with Wainwright on track to return to the rotation and the bullpen resetting with the help of some deep starts, the club is likely to add back that extra position player within the next few days.

• Matheny entered Wednesday intending to stay away from reliever Carlos Martinez for at least another day. Martinez threw 59 pitches in a spot start Monday. Nick Greenwood, who threw 60 pitches Monday, was available Wednesday, though the Cardinals' preference was to also stay away from him unless absolutely necessary.

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.