At 3:12 p.m. yesterday, Boomer Esiason walked over to Frank Reich, his roommate and understudy, and said, "Congratulations, buddy. You're the starter. I know you can do it."

Reich, sitting at his locker, looked at a reporter and said, "Is that Boomer-official or really official?"

It was officially official. Maryland Coach Bobby Ross said yesterday that Esiason, who has started the last 24 games at quarterback for the University of Maryland, will not start today at 1:30 p.m. against 16th-ranked Pitt (2-0) in Byrd Stadium. He will be examined this morning before the game, but probably will not play even if Stanford Lavine, the team physician, says Esiason's right arm is healthy enough for action.

"Boomer's playing is still uncertain, and since Frank has played well in practice all week, he will start," Ross said.

Esiason suffered sprained ligaments in his right (nonthrowing) shoulder last Saturday when sacked in the first half by a West Virginia linebacker blitz. He practiced only one day this week.

"I'm going to try to convince Doc Lavine I can play," Esiason said yesterday. "Tuesday was probably too early to try to come back, but I've been trying to convince everybody all week that I can play. It feels all right, but I don't know if it can take a solid hit."

Reich, a junior, has completed two of three passes at Maryland. He is 6 feet 4 and 205 pounds, the same height and a little heavier than Esiason. But Reich isn't as quick or mobile as Esiason, a senior whom college and professional scouts consider one of the best quarterbacks in the nation.

Reich's passing has been almost flawless this week. Yesterday, in a light 30-minute practice in Byrd Stadium, he didn't miss a pass. "On Tuesday, he had probably the best practice any player on our team has had this season," said Ross. "I felt comfortable with him running things already, and after the way he's practiced this week, I feel even better."

Reich, as softspoken as Esiason is outgoing, said, "I did have a good week of practice--probably the best since I've been here--but that doesn't mean I'll do it in the game. I do feel really comfortable, though. This is exciting for me. This is it."

Esiason and Reich say they talked about this situation all week. "I told him, 'This is your chance,' " Esiason said.

Reich said, "I know Boomer doesn't like not starting one bit. But he also told me he wouldn't want to play if it wouldn't help the team. If he can play tomorrow, fine. I figure it's no shame playing behind one of the best quarterbacks in the country."

Offensive Coordinator Joe Krivak, who usually gives Esiason a package of plays from which he can select one, said Reich will receive a similar package.

Esiason has always been eager to throw deep. And Reich said, "I love to throw long myself. When I get the opportunity, I'll go for it."

Brian Baker, a defensive end who has practiced against Reich a lot in four years, said, "Frank can throw and he's intelligent; we're safe."

Reich will be breaking in against a team that is second in the nation in team defense. The Panthers (2-0) haven't allowed a touchdown this season, and have permitted only three in the team's last 24 quarters of play. The Panthers have had a week's rest while the Terrapins have had a week of recuperation and self-examination after last week's 31-21 loss to West Virginia that dropped them out of the top 20.

Maryland has more to worry about than its quarterback; the offense has not played well in either game this season. The locker room has been noticeably quiet this week. "It's more serious in here than any time the last two years," Baker said. "This is a week of retribution; it's been very serious this week."

It's been a strange week for kicker Jess Atkinson. He lives in the same room as Esiason, Reich and Alan Sadler, who punted terribly last week. "Can you imagine sitting in that room with Boomer worried about his arm, and Alan telling Frank, 'Don't get backed up because I don't want to punt out of the end zone?' The whole room is freaking out; I try not to come home until curfew."

And in another sidelight, guard Shawn Benson of Maryland will be blocking his younger brother Troy, a linebacker who leads Pitt in tackles this year. "I called him last night and told him I was going to whip his butt, and he told me the same thing," Shawn said. "We acted like two clowns."

Although almost everyone in College Park is talking about the Terrapins' starting a new quarterback, the Panthers will be playing only their second game with sophomore John Congemi at quarterback.

In other games involving area teams today, Virginia (3-0) travels to Raleigh for an Atlantic Coast Conference game against North Carolina State at 12:30. The Cavaliers' chance of remaining undefeated would be a lot better if their two best running backs--Antonio Rice and Quentin Walker--weren't out with injuries.

Navy (0-2), off to its worst start in 14 years, is at home against Lehigh at 2. Howard (1-2) plays South Carolina State, a Mid-Eastern Athletic Conference power, at 1 at Howard Field.