Rookie pitcher Brian Bannister, sidelined by a strained right hamstring since April, will make his return to the Mets staff on Friday night when he is scheduled to start against the Philadelphia Phillies.

Bannister, a son of former major league pitcher Floyd Bannister, earned a spot in the rotation during spring training and won two games in April. He then strained his hamstring running the bases during a game in San Francisco and was placed on the 15-day disabled list on April 28. He reinjured the hamstring in a minor league rehab start and was transferred to the 60-day disabled list on May 30.

“We’re going to monitor his pitches and his stuff,” manager Willie Randolph said. “He’s been throwing a lot of pitches and we have the luxury of seeing him pitch.”

Bannister will start in Orlando Hernandez’s spot on Friday, with El Duque pushed back, probably to next week.

“He’s fine,” Randolph said of Hernandez. “It’s just a precaution.”

The Mets are undecided about their pitcher Saturday night, and there is the possibility that left-hander Oliver Perez will be promoted from Triple-A Norfolk to make that start. Perez was obtained from Pittsburgh along with reliever Roberto Hernandez in the July 31 trade for outfielder Xavier Nady.

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The Mets designated outfielder Ricky Ledee for assignment last to make room on the roster for right fielder Shawn Green, who was acquired from Arizona on Tuesday.

Ledee, claimed on waivers from the Los Angeles Dodgers on Aug. 8, was 1-for-15 in 11 games with the Mets and is batting .206 for the season.

In another move, the Mets transferred reserve catcher Ramon Castro from the 15-day disabled list to the 60-day DL. Castro was placed on the 15-day list on Aug. 4 with a sore left rib cage. He tore the medial meniscus of his left knee prior to a rehab game with the Brooklyn Cyclones on Aug. 21 and underwent surgery to repair his knee on Wednesday.