Georgetown guard Derrick Jackson was back in Sibley Hospital yesterday, and team physician Carl MacCartee said it will be Monday at the earliest before a decision is made as to whether Jackson can play in the Hoyas' next National Invitation Tournament basketball game.

Jackson, Georgetown's all time leading scorer who was hospitalized for treatment of a bleeding ulcer 10 days ago, accompanied MacCartee to watch the Hoyas nip Virginia, 70-68, in overtime Wednesday night in Charlottesville. But Jackson returned to Sibley yesterday.

MacCartee said there should be no cause for alarm that Jackson is still hospitalized. "He seems to be doing well," the doctor said. "We put him back in the hospital for observation and rest.

"We'll let it go for three or four days and see what happens Monday . . . What determines when he's healthy again? His blood count, his vital signs, all the things we can measure.

"Everybody heals at a different rate," MacCarte said. "That's what makes it so unpredictable."

If MacCartee and the specialists give Jackson a green light Monday, there is question of how much stamina he could have for a game that could be played as early as Tuesday. The date and site will not be determined until after tonight's Dayton at Fairland game.

"If the doctor tells me Derrick's healthy," Coach John Thompson said, "Derricks will have totell me how much he can play . . . If Ted Williams was out for Boston and they were in the World Series and the doctor told the manager that he was well, would you put him in the game as a pinch hitter or what?

"You've got to be kidding. Dama right, you put him out there. I'd rather seeDerrick Jackson miss some baskets than somebody else."