ST. LOUIS -- In an effort to expedite Carlos Martinez's return to the active roster, the Cardinals will transition him into a relief role for the remainder of the season.

The move does not indicate a long-term shift in the organization's plans for Martinez, as he will report to Spring Training ready to reclaim his rotation spot. But it will allow Martinez to return from the 10-day disabled list quicker than he would have if the Cardinals sent him on a rehab assignment to build up the arm strength necessary to carry a starter's workload.

"If you're going to go down that starting path and you're starting at ground zero, the likelihood of him being back would be sometime in mid-September," said John Mozeliak, president of baseball operations. "And we've done that twice this year and ended up in the same place after a few starts."

How interim manager Mike Shildt will deploy Martinez out of the 'pen remains in discussion, but Martinez will not be earmarked solely for a multiple-inning role.

"We've got another weapon that we can use when it's necessary," Shildt said. "If that helps take the strain off other guys, then it will."

Martinez, who is on the DL for the third time this season, is no stranger to pitching out of the 'pen, having spent his first two seasons (2013-14) as a reliever.

Martinez threw a 30-pitch bullpen session at Busch Stadium on Monday and plans to repeat the exercise in a few days. He'll then head out on a brief rehab assignment to give his healing right shoulder one final test.

"I feel great right now," Martinez said. "I'm comfortable with all my pitches."

Although the Cardinals are altering Martinez's fit on the pitching staff, they won't do the same for Michael Wacha. Mozeliak confirmed that Wacha, who could begin a rehab assignment as early as next week, will build back up as a starter. Wacha has been sidelined by a strained left oblique since June 21.

Roster reshuffling

The Cardinals plan to make a pair of roster moves during the series with the Nationals, beginning with activating Tyler O'Neill from the DL on Tuesday. O'Neill, who has been sidelined by groin inflammation, went 4-for-13 during a three-game rehab stint at Triple-A.

O'Neill returned to St. Louis on Monday, along with Brett Cecil, who is expected to come off the DL on Wednesday. Cecil (inflammation in right foot) made four appearances with Memphis, including pitching in back-to-back games over the weekend. Over four scoreless innings, Cecil scattered two hits and a walk and struck out two.

"I think in this particular case, we need to trust that [he's] at a point where he can contribute," Mozeliak said of Cecil, who has a 5.70 ERA this season. "Look at where he was two years ago; I think ... his rehab has gone very well. I'm encouraged at where he's at, and I certainly hope that he's ready to be a positive contribution out of that bullpen."

Medical report

Adam Wainwright threw a scoreless inning to open a rehab assignment with Class A Advanced Palm Beach on Monday. After allowing a leadoff single, Wainwright struck out the next two batters he faced.

A hand specialist gave Yairo Munoz good news on Monday, as it was determined that Munoz's right wrist is not as severely sprained as initially feared. The Cardinals are optimistic that Munoz will be cleared to start swinging by the end of the week and ready to come off the DL around his eligibility date of Aug. 21.

William Fowler was scheduled to meet with team physician George Paletta on Monday to check on the healing of his fractured left foot. The Cardinals hope that visit will provide a better timeline for Fowler's recovery.

A possible reunion?

Mozeliak was among the many surprised to hear about Rick Ankiel's interest in trying to play professionally again. After pitching in an exhibition game, Ankiel shared on the Fox Sports Midwest pregame show that he'd like to take one more shot at pitching in the Majors.

Could that come with the Cardinals?

"It's intriguing," Mozeliak said. "But I think the timing of it right now would be very difficult for us to chase. But in the offseason, I do plan at some point to speak with him."

Ankiel, who hasn't played since 2013, last threw a pitch in the big leagues in '04.

Rosenthal's recovery

Trevor Rosenthal, who underwent Tommy John surgery a year ago, wrote on Twitter that he will be holding a workout in October for clubs interested in signing him. Rosenthal chose to complete his rehab as a free agent after the Cardinals released him in the fall. The Cardinals do plan to reach out to Rosenthal's representatives to discuss the possibility of a reunion.