Lopes' cancer was found after he went through a routine examination with the rest of the coaching staff on Feb. 12, two days before pitchers and catchers reported to camp.
"Of course what Davey has is very serious, but the doctor feels like everything is going to be fine," Phillies manager Charlie Manuel said following his team's 3-1 win over the Pirates Monday afternoon. "The medical department feels like ... everything is going to work out for him - he's just going to miss some time."
Lopes, 62, is entering his second season with the Phillies coaching staff. Jerry Martin, a minor league outfield and baserunning coach in the organization, will take over temporarily as first base coach and outfield coordinator.
Phillies pitcher Jamie Moyer's eyes began to redden while talking about Lopes on Monday. Moyer and his wife, Karen, established a foundation in 2000 to support and offer comfort to children with cancer and kids who have lost loved ones to cancer.
"Hopefully it was caught in time," Moyer said. "While dealing with families and kids with cancer in Seattle and throughout the country, one thing I've learned is early detection is huge, and that sounds like that's the case. ... By catching something early, hopefully it'll be a positive story."
Lopes was manager of the Brewers from 2000-2002. A former four-time all-star, he played the majority of his 16-year career with the Los Angeles Dodgers.
Lopes, who led the National League in stolen bases in 1975 and 1976, helped the National League East champion Phillies break a major league record in stolen base efficiency in 2007. The Phillies swiped 138 stolen bases in 157 attempts (87 percent).