Houston Oiler offensive lineman Greg Sampson was in stable condition today following emergency brain surgery for a blood clot believed caused in a training-camp collison with another player 13 days ago, officials at Methodist Hobital said.

Sampson, 28, was reportedly resting comfortably following the three-hour operation that began at 10 p.m. Friday for removal of a subdural hematoma, or blood clot in the brain.

Doctors said they doubted Sampson, the mainstay of the Oilers' offensive line and an honorable mention All-Pro last season, would ever play football again, but said the 6-foot-6, 270-pounder should be able to live an otherwise normal life.

An Oiler spokesman said today that the team physician told the club that Sampson "was doing superbly" and that he had been moved to a private room from the intensive care unit. The spokesman quoted Dr. Thomas Cain as saying Sampson was "awake, alert and cracking jokes."

The clot apparently developed after Sampson, a seven-year veteran, collieded with a teammate during a July 22 practice session at the Oilers' training camp in San Angelo. He began complaining of nausea and severe headaches the next day, but two days of tests proved negative, and Sampson resumed practice.

Sampson was Houston's first draft choice as a defensive lineman in 1972. He was switched to offense in 1974.