By Rob Maaddi
The Associated Press

CLEARWATER, Fla. - Tug McGraw is undergoing neurological evaluation at the Moffitt Cancer Center in Tampa and is scheduled to have surgery early this week.

In a statement released by the hospital through the Philadelphia Phillies, Dr. Steven Brem said evidence of a malignant brain tumor is "inconclusive." Brem is the program leader of Moffitt's neuro-oncology program and an expert in brain mapping and neuronavigation.

Officials declined to release any further information about the planned surgery.

Two sources close to the former star pitcher, who spoke on condition of anonymity, previously said that doctors at Morton Plant Hospital in Clearwater diagnosed McGraw with a malignant brain tumor after he was hospitalized on Wednesday.

The 58-year-old McGraw was hospitalized Wednesday. He has been a special spring training instructor for the Phillies the last two seasons.

McGraw helped the Phillies and New York Mets win World Series during his 19 seasons in the major leagues. The left-hander went 96-92 with a 3.14 ERA and 180 saves.

McGraw popularized the phrase "Ya Gotta Believe" with the Mets during their improbable pennant run in 1973, and later closed out the Phillies' only world championship in 1980.

McGraw has received many visitors during his hospital stay, including former Phillies outfielder Jay Johnstone, Hall of Famers Harmon Killebrew and Brooks Robinson and former Astros outfielder Jimmy Wynn. McGraw had looked forward to playing in Sunday night's legends game sponsored by the Major League Baseball Players Alumni Association.

"He was fun, always kept everybody laughing," said Johnstone, who played with McGraw from 1975-78. "Tug will find a way to get out of this."