The Redskins lost much more than their first game of the preseason today.

They probably lost all-pro Mike Nelms as a kick returner for the next month because of a broken thumb incurred near the end of New England's 19-10 victory. Terry Metcalf probably will become the return man.

They lost linebacker Brad Dusek for four to six weeks because of a dislocated left shoulder. He probably will be placed on injured reserve.

And they lost what Coach Joe Gibbs called "our tempo, our concentration, our ability to make something happen in the second half on offense."

Although Gibbs finished his first preseason as Redskin coach with a 3-1 record, the injuries and the sudden lapse by the offense after halftime hardly left him in a mood to celebrate before starting work for the season opener against Dallas Sunday at RFK Stadium.

"A lot of things will be answered in my mind when I see how we do next week," Gibbs said. "I had a good feeling in the first half, but then we just couldn't get rolling in the second. We lost our sting, we couldn't get anyone to pick us up. It's a puzzle to me. And losing Mike and Brad really hurts."

The Redskins had taken a 10-6 lead after the first half. But they had only three more first downs and 68 total yards in the second to fall to a New England team that played most of the way without regulars Stanley Morgan, Harold Jackson, Horace Ivory and Vagas Ferguson.

The Patriots offset Joe Washington's five-yard touchdown run and a 20-yard field goal by Mark Moseley with four field goals by John Smith and a five-yard scoring pass from quarterback Matt Cavanaugh to tight end Lin Dawson in the fourth quarter.

Gibbs went with reserve quarterback Tom Flick and a bunch of reserves the last one-third of the game, which contributed to the Redskins' inconsistency. As long as the first-stringers played, Washington moved the ball adequately against the top Patriot defenders.

"I was pretty happy with the way we played in the first half," said Redskin quarterback Joe Theismann, who completed 10 of 17 passes for 130 yards and had one interception. "It was a good confidence-builder for the starters. I really feel good about the offense, even with the mistakes we made."

Gibbs now has two problems: reducing the roster from 50 to 45 players by 4 p.m. Monday, and deciding what to do with such ailing players as Dusek, Nelms and rookie wide receiver Charlie Brown.

Nelms feels he might be able to play defensive back with the thumb in a cast. If so, he probably will be kept on the active roster.

The Redskins have two options with Dusek and Brown, who has a sore knee. They can place them on injured reserve before 4 p.m., but both would have to clear waivers to return this year to the team.

If they are kept on the final roster and then moved to injured reserve, the club would have to bring them back by using two of the three moves it is allowed per season off that list.

Since the Redskins now have only five healthy linebackers, they definitely will have to pick up someone to replace Dusek, either by trade or through waivers. They still are looking for another defensive back.

Center Dan Peiffer's knees are troubling him, so he, too, may be headed for injured reserve.

Gibbs' other cuts probably will come from the wide receivers, where Virgil Seay is vulnerable; the defensive line, where Pat Ogrin could be the odd man out; running back, where Otis Wonsley may be a victim of too many talented competitors, and cornerback, where rookie LeCharls McDaniel appears the most likely choice.

"I can't see Nelms returning punts with that thumb," Gibbs said. "Terry would have to take over for him. We've been giving Metcalf work (he returned kicks today) and now he's going to have to take on an extra load."

Metcalf, once one of the league's best kick returners when he played for St. Louis, was scheduled to handle returns today, a stroke of good fortune for the Redskins. He handled three punts, bringing one back 15 yards, and two kickoffs.

"I didn't do any returning last year (in Canada) so I was a little rusty. It felt a little shaky at first," Metcalf said. "But I guess if they need me to fill in for Mike, I'll be getting plenty of work. It's okay with me. I like to return kicks."

The Redskins started this game as if they were going to roll to an easy victory. On their first possession, they moved from the 22 to the Patriot two before being stopped by their own mistakes.

A 38-yard pass from Theismann to Art Monk on a simple go pattern and a personal foul against the Patriots helped get them close. Then guard Jerry Scanlan couldn't block penetrating cornerback Mark Haynes, who stopped Joe Washington for a six-yard loss to the seven. On third down, a completion to Ricky Thompson could pick up only five, so Moseley had to kick his 20-yarder with 8:44 gone in the quarter.

With quarterback Grogan missing on five of his first six passes, New England was spending most of the half watching Theismann control the ball. On the Redskins' third possession, he found Monk over the middle for 17 yards and Thompson for 27 more on a fine leaping catch at the Patriot 29.

Joe Washington picked up nine yards on a sweep, John Riggins ran up the middle for six and Rick Walker caught a five-yard pass from Theismann that put the ball at the nine. Monk then caught a Theismann pass at the goal line. It appeared he had scored, but officials ruled he was down at the one.

The right side of the line jumped off on first down for another error. But this time Joe Washington erased the mistake by sweeping right end from outside the five, then cutting in behind fine blocks from Riggins, Don Warren and Mark May to score. Moseley's conversion made it 10-0 with 12:39 remaining in the second period.

For the Redskin offense, that was the game. Hurt by poor field position, Washington moved across the 50 just twice more, once because of an interception by Mark Murphy. A punt and a Patriot interception cut off both drives before they could worry the opposition.

Meanwhile, Grogan and Cavanaugh gradually cut into the Redskins' lead. Grogan had success throwing long from the shotgun against nickel coverage, setting up one of Smith's field goal with a 50-yard completion to Preston Brown. Another field goal came after a 32-yard punt return by Roland James and five completions by Grogan.

Metcalf's fumble on a botched handoff from Flick led to Smith's third field goal, from 40 yards, and Smith made a 37-yarder early in the fourth to give New England its first lead, 12-10.

A 29-yard punt by Mike Connell moments later was downed at the Redskin 46, and in 10 plays Cavanaugh produced a touchdown on his pass to Dawson.