Derrick Jackson, Georgetown University's all-time leading basketball scorer, was hospitalized shortly before the Hoyas' ECAC playoff loss to Virginia Commonwealth Wednesday night because of a bleeding ulcer.

Jackson has had the condition since childhood but it had not flared up since he was eight years old. The senior from Wheaton, Ill., remained in Sibley Hospital last night and is expected to be released over the weekend, according to Georgetown Coach John Thompson.

Thompson said that Jackson's doctors have told him that, barring complications, the 6-foot-1 guard should be available for postseason play next week if the Hoyas get a longshot at-large bid to the NCAA tournament or a berth in the National Invitation Tournament.

Depending on tournament results the next two days, it appears that as many as eight or nine of the 11 at-large bids are reasonably set and that the Hoyas will be competing against almost 20 other schools for the first-round NCAA bids.

Thompson said he is hoping that the six-member NCAA Basketball Tournament Committee will take into consideration the difficulty of his team's schedule and Jackson's illness when they determine Sunday morning whether the Hoyas' 21-6 record is good enough for a bid.

Regardless, Thompson was a relieved man yesterday because he had thought that Jackson's stomach disorder was far more serious. He explained how the impact of Wednesday's events had unsettled him, and Jackson, from his hospital bed, told why he had hid his illness from the coach.

Jackson, the team's captain and leader, said he had felt "pretty bad for two-three days" before being "real, real sick like I was yesterday.

"I ran the skeleton offense drill and I felt faint then. But I didn't want to say anything then. I felt there was the chance it was the ulcer. I thought if I rested in the afternoon and felt the same as I did during shooting practice, that I could play.

"But I felt worse and worse, and gave it up, I guess what I was trying to do was I wanted to play and keep the rest of the team from knowing about it, so it wouldn't affect them psychologically. But it did. Coach Thompson broke down when he told the team.

"I wanted them to think about the game, not me. But they didn't do that."

In fact, Thompson's mind was anywhere but on the game, which the Hoyas lost to hot-shooting VCU, 88-75.

The tall coach showed little of his normal emotion on the bench.

He said he had remained behind at Georgetown when the team bus left for GW's Smith Center at 5:45. He arrived there an hour later. Then he received a message from Mary Fenlon, Georgetown's academic advisor and basketball staffer who had accompanied Jackson to the hospital.

"Mary sent a message that she was not coming to the game and was going to stay with Derrick," Thompson said. "That upset me. I thought, 'Maybe they were trying to keep something from me.' It was such a very, very unsettling thing.

"It's bad enough to have 13-14 young men who are basically somebody's children you have responsibility for. The whole reality of it came to me when I realized he could have passed out on the floor if he had played. In hindsight, I noticed changes in him late last week. I kept asking him if something were wrong and he said, 'No.'"

Jackson said yesterday that the condition runs in his family, that both his sister and mother have had ulcers. He said the doctors told him that people, like him, who keep emotions bottled up, are most susceptible to the illness.

Jackson said he felt much better yesterday and added, "I'm ready to play (basketball) right now. But the doctors are pretty cautious."

"That's not something I talked to him about," said Thompson. "But I feel good they think he's healthy enough there's a possibility of him playing. It gives me an indication he's well and not in grave danger, which I was scared of."

Georgetown's NCAA situation is basically a numbers game.It appears that at-large teams will be picked from at least four conferences (Atlantic Coast, Southwest, Metro Seven and Western Athletic) and that independents Marquette, DePaul, Detroit and Notre Dame all have at-large bids clinched.