Returning from a five month-long medical leave of absence, longtime Phillies president and CEO David Montgomery will assume the position of chairman while Pat Gillick continues to serve as president, the team said Wednesday.

The shake-up could pave the way for a new Phillies president in the near future, as Gillick, the architect of the 2008 world-championship team, said just last week he is not interested in serving in the role longterm.

Gillick, 77, had served as the Phillies' interim president since late August, when Montgomery took his leave.

Montgomery, 68, underwent surgery in May to remove cancer from his jawbone. He said Wednesday in a telephone interview that he is in good health and looking forward to traveling to Clearwater for spring training. His most-recent tests in December came back clear and he is scheduled for another in six months, he said.

Montgomery assumes the position held by Bill Giles, whom Montgomery succeeded as Phillies president in June 1997. Giles, who as chairman did not influence baseball decisions, assumes a chairman emeritus title.

Asked if he envisioned Gillick serving in the president's role longterm, Montgomery said, "I think that's really up to him."

"I'm just pleased that he's willing to give us the opportunity to take advantage of him doing it now, which will help (general manager Ruben Amaro Jr.) and help the whole process of us getting back," Montgomery said. "What happens in that role longterm, that's going to be his decision, not mine. ... That's really going to be Pat's call."

Montgomery, who grew up in Roxborough, has been with the Phillies since 1971, when he started as an entry-level ticket salesman. After advancing through the ranks of the organization, he was in charge for parts of 18 baseball seasons, including the team's five consecutive National League East titles from 2007 to 2011.

"Will I be the one that (former general manager) Ed Wade tapped to go with him to talk (Jim) Thome into coming or to try to sign Ryan Howard when we were facing arbitration numbers? No, that won't be me," Montgomery said. "And I'm OK with that, to be honest with you."

Montgomery, the team said, will "remain active in Philadelphia civic, business, sports, and charitable endeavors, and also will maintain his close association with Phillies fans, customers, and sponsors. He will continue to be very involved in Major League Baseball committees and projects, as well."