Winokur, the celebrated Tracy Turnblad of the 1960s-set musical comedy, pulled a calf muscle during Act One Jan. 29, halting the show briefly. The injury happened during "Mama, I'm a Big Girl Now" and Winokur continued for several scenes before bowing out. Understudy Katy Grenfell jumped into the show during the reprise of "The Nicest Kids in Town," a spokesman told Playbill On-Line. Grenfell played the rest of the Wednesday night show and also played Thursday Jan. 30. Shoshana Bean will play the role Jan. 31.

Winokur's injury is being judged day-to-day, a spokesman told Playbill On-Line Jan. 31, and she may very well appear over the weekend to prove the show's anthem that "You Can't Stop the Beat."

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Winokur was able to tape a segment for "Live With Regis and Kelly" Jan. 30 (her non-dancing performance of "Good Morning, Baltimore" aired the morning of Jan. 31) and is under a doctor's care.

Understudy Katy Grenfell has played the lead role before in Winokur's absence, but Jan. 29 was the first time she jumped into it in mid-show. The injury was technically listed as a pull of the medial gastroc, a spokesman said. Winokur is considered a favorite to be nominated for a Tony Award for Best Actress (Musical) in May.