ARLINGTON, Texas -- Former Texas manager Johnny Oates has been diagnosed with the most aggressive form of primary brain tumors.

Oates, who made his illness public Thursday, will undergo surgery later this month in Virginia. The average survival rate is only about a year.

Johnny Oates says in a statement, 'I appreciate all of the kind words and prayers that I have received.' (AP)

"My family and I have great strength at this time, and I have put myself in the hands of the Lord," the 55-year-old Oates said in a statement released by the Rangers.

"I am optimistic about my future. I appreciate all of the kind words and prayers that I have received," Oates said.

"Please assure everyone that I am at peace," Oates told the Fort Worth Star-Telegram in a telephone interview. "It's not something I would have scripted for my life at this time, but I'm hopeful I'll come through this and have five or six more wonderful years to spend with my family."

During the surgery in Richmond, Va., doctors will remove as much of the glioblastoma multiforme tumor as possible. Radioactive pellets or a chemotherapy wafer could be inserted into his brain to more directly fight the cancer.

"Some people choose just to go with radiation, but if you're going to have surgery, it makes it easier to do it now, before the tumor gets any larger," Oates said. "They tell me there are people with the exact same thing who are five years into it now and still going."

Oates, who lives in Matoaca, Va., experienced the first symptoms in late October when he started feeling weakness in his left side. He was forced to cut short a radio interview before Game 2 of the World Series on Oct. 28 because of weakness and slurred speech.

He underwent tests and was told of the diagnosis Monday. "We're praying for a miracle," Oates said. "Who knows? This thing may disappear. If not, I'm confident the doctors will have the wisdom to know what to do with it and what to do next. ...

"I don't remember much about what they said, and I sure can't pronounce what they called it. All I remember is that they said it's not a good one to have."

Jerry Narron, who was on Oates' staffs in Baltimore and Texas from 1993 until replacing him as the Rangers manager in May, was shocked by the news.

"This is somebody that I respect as much as anybody in baseball or in my life," Narron said. "I saw him Monday and he looked great and was in great spirits. I feel like I am going through this with him. All my thoughts are with him. I just hope he gets better."

Oates managed the Rangers to their only three AL West titles (1996, '98 and '99), but Texas finished last in 2000. Then, despite the addition of $252 million shortstop Alex Rodriguez this season, the team was 11-17 and already 10½ games behind Seattle when Oates resigned under pressure May 4.

In six-plus seasons with the Rangers, he had a 506-476 record, a .521 winning percentage. He ranks second in team history in wins, winning percentage and games managed.

Oates was the AL's co-manager of the year in 1996, his second season in Texas. He shared the award with Joe Torre of the New York Yankees, the team that beat the Rangers in the first round of the playoffs all three times.

Before joining the Rangers, Oates managed the Baltimore Orioles from 1991-94 and had a record of 291-270. He and Frank Robinson are the only people to ever play for, coach and manage the Orioles.

In all, Oates spent 34 years as a player, coach and manager in professional baseball.

The glioblastoma multiforme, which contains a mixture of cell types, is one of the most difficult brain tumors to treat, according to the American Brain Tumor Association. While one cell type is responsive to treatment, other types wait their chance to take over.

Headaches, seizures, memory loss and changes in behavior are the most common symptoms. Surgery, chemotherapy and/or radiation therapy are among the treatments.

Dick Howser and Dan Quisenberry, the manager and relief pitcher for Kansas City's only World Series championship team in 1985, both died as a result of brain tumors.

Howser died June 17, 1987, about a year after his tumor was diagnosed. He had undergone three operations and experimental treatment. Quisenberry, known for his submarine delivery and witty personality, died Sept. 30, 1998, about nine months and two surgeries after his tumor was discovered.

Josh Gibson, one of the best hitters in the Negro Leagues before the major leagues integrated, died Jan. 20, 1947, more than three years after being diagnosed with a brain tumor he refused to have treated with surgery.

As a player, Oates played 593 games with the Orioles (1970, '72), Atlanta (1973-75), Philadelphia (1975-76), Los Angeles (1977-79) and New York Yankees (1980-81). Primarily a backup catcher, Oates had a career average of .250 with 14 homers and 126 RBI.

After managing three minor league teams, Oates became the first-base coach for the Orioles in 1989. He served in that position until he replaced Robinson as manager on May 23, 1991.