The Redskins' injury situation worsened yesterday when it became apparent tackle George Starke and tight end Gregg McCrary would not be able to play Sunday in Chicago. To replace McCrary, Washington signed Rich Caster, the former New York Jets and Houston Oilers star.

Monday, Coach Joe Gibbs had thought Starke's broken right hand would be healed sufficiently to allow him to start against the Bears. Gibbs was not aware that McCrary hurt his back and began suffering spasms that day, following a light workout.

After an examination by a hand specialist yesterday, Starke was instructed not to play for at least two more weeks, leaving the Redskins without a bona fide backup tackle. General Manager Bobby Beathard was trying to find a replacement for Starke, either through a trade or off the waiver list, although Starke will be kept on the active roster.

McCrary's back problems became so severe that he was admitted to Sibley Memorial Hospital, where he was in traction last night.

With Gibbs running a predominantly two-tight-end offense, the team suddenly needed a third tight end. Caster has been available since a brief stint with New Orleans. The Saints dropped him after he dropped a would-be touchdown pass in a 21-14 loss to San Francisco Sept. 27.

"Rich still has good speed, he's run some good 40s on grass at Houston," Beathard said. "He also is a fine pass catcher. He's also versatile. He can play outside and tight end."

Caster was one of Joe Namath's favorite targets after the Jets drafted the tight end on the second round in 1970. Caster caught between 31 and 47 passes yearly from 1972 to 1976.

A three-time all-pro, Caster, 32, is in his 12th pro season. He caught 27 passes for 341 yards last season.

"We are looking for a tackle, too, because we only have seven linemen, which is one too few," Gibbs said. "That's the same situation we got caught in at Philadelphia and it hurt us."

Guard Russ Grimm, slowed by a knee injury, practiced yesterday and is likely to start Sunday. Tackle Mark May, who has a hip pointer and leg pull, will start.

"If Russ does start, we're really going with five rookies on the offensive line," Gibbs said.

Another injured player, cornerback Lemar Parrish, appears healthy enough to start this week, as does halfback Joe Washington. But Gibbs was pessimistic about the availability of defensive end Mat Mendenhall and fullback Wilbur Jackson.

Gibbs also said Terry Metcalf would replace Clarence Harmon on the special teams and as the third-down pass-catching specialist. Harmon is out for at least six weeks with a fractured right shoulder.

"Terry is something; he hasn't missed a down this year," Gibbs said. "Now I'm anxious to see how he does on special teams. He's enthusiastic about playing there."

Harmon was the unofficial captain of the special teams.