After spending two weeks in the Redskin training camp almost unnoticed, this was going to be kicker Pedro Posadas' big moment. He was going in at the end of today's scrimmage against the Baltimore Colts to try for a game-tying field goal.

But Coach Jack Pardee changed his mind. Instead, he sent in Mark Moseley, who was drooling over the wider, college-size goal posts. While Posadas watched in dismay, Moseley's kick was blocked and the Colts preserved a 6-3 triumph.

It was that kind of a day for the Redskins. They played with only five offensive linemen (including three centers) and lost another defensive lineman, Perry Brooks, to injury. The Redskins allowed only one decent offensive gain, but that 45-yard touchdown scamper by Ben Gary off a short pass proved to be the difference.

Brooks, a promising reserve tackel, ruptured a biceps tendon in his right arm and will be out for about three weeks. Reserve offensive lineman Jim Harlan, who has a neck injury that could end his career, is returning to Washington for further medical evaluation.

Harlan has a pinched nerve that could render him paralyzed if aggravated. The Redskins hope further tests will indicate whether the injury can be relieved and his future as a player salvaged.

Brooks, who started last season after Diron Talbert was injured, said he didn't know how he tore his upper arm.

"We were short of linemen and I played," he said. "It's just something that happens. Thank goodness it is just for three weeks."

The Redskins already were short of defensive linemen before Brooks went down. And their offensive linemen were reduced because guard Jeff Williams was held out of action. He has a nose injury that has resulted in two black eyes.

"Considering the way our offensive linemen were, I was pleased we even moved the ball," Pardee said. "This was more of a chance to study matchups. We couldn't really perform that well as a team."

There were some standouts among the young players. Fullback Mike Jones, receivers Glenn Starks and Tony Hall, defensive end Jessie O'Neal, quarterback Kim McQuilken and linebacker Neal Olkewicz all performed well.

Jones, a rookie free agent from Grambling who has been a surprise in camp, highlighted the final Redskin drive in the 96-play scrimmage.

The first time Jones touched the ball, he gained 13 yards around left end. Then he picked up nine around the right side, followed by a seven-yard scamper that started up the middle and finished down the left sideline.

After a four-yarder by Louis Carter, Jones broke for three yards, setting up third and three on the Colt 27. Under the rules of the scrimmage, the Redskins had to make a first down on the next play or the ball would be returned to the Washington 35. They tried a draw, but Jones ran into his blocker, slipped and fell.

But Washington wasn't done. On its next series, Gary Valbuena completed two passes for 29 yards and Jones romped for 13 more to move the ball to the Baltimore 21. That's when Moseley, on the final play of the day, failed on his 39-yard attempt.

"I was licking my chops," said Moseley, who made a 41-yarder earlier. "It was good for me, to get into that type of situation so early in the season. I hit the ball good but the guy (Greg Fields) was four yards into the backfield. It's tough to avoid a guy that deep."

Posadas, a rookie from Louisville who has no chance of making the team, had to be content with the kicking of field goals after the scrimmage. He made three of four, the last one from 45 yards out.

Jones, who spent some time during the spring with Edmonton of the Canadian Football League, totaled 47 yards in six carries. Clarence Harmon had 25 yards in three tries and Tony Green 21 on eight. Valbuena completed four of six passes for 65 yards.

Hall, the 5-foot-9, 165-pound speedster from Knoxville, Tenn., grabbed one pass. Starks, a free agent from Texas A&I, had two receptions for 40 yards.

"We learned that Tony (Hall) could go inside and catch the ball," said Pardee, who is impressed with the rookie receiver. "And we found out that Starks can catch the ball too."

In passing drills that preceded the scrimmage, quarterback Joe Theismann got off to a rugged start against the Colt first string. His first attempt was intercepted by Saunders Shiver.

Next, he was sacked by Joe Ehrmann. But later he got warmed up and completed six of nine for 23 yards. The Colts' Bert Jones completed only two of eight for 23 yards and suffered one interception, by Gerard Williams on a tip from Kenny Houston.

Earlier in a seven-on-seven drill, Theismann was 16 of 25 for 202 yards and two touchdowns, both to John McDaniel. McQuilken, who continues to look sharp, was 11 of 15 for 103 yards. Jones completed nine of 19 for 109 yards and one interception (by Mark Murphy). Backup Greg Landry was 12 of 18 for 160 yards.

Washington was especially effective in hitting backs swinging out of the backfield - Stan Winfrey had six catches - and connecting with tight ends.

NOTES: Fullback Don Testerman banged up a shoulder but should be able to practice next week...Rookie Frank Collins sprained a knee Friday and did not play...Gary ran through the entire Redskin defense en route to his touchdown after taking a short pass from Mike Kirkland. Cornerback Ray Waddy had the last shot at him, at the Redskin 40, but missed. Rookie linebacker Barry Krauss also was outstanding for the Colts...O'Neal had a sack and a blocked pass for Washington. CAPTION: Picture 1, Pete Wysocki (50) and Mark Murphy break up pass intended for Colt wide receiver Randy Burke. Colts won scrimmage, 6-3. By Richard Darcey - The Washington Post; Picture 2, Redskin rookie Mike Jones gains first down on block by Fred Dean of Colts' Greg Marshall. By Richard Darcey - The Washington Post