In a surprising move, the Washington Federals waived starting middle linebacker Kevin McLain yesterday.

McLain, a No. 1 draft pick by the Los Angeles Rams in 1976, was signed by the Federals in April and started the last five games.

"I had lost a little respect for the coaching staff and I think they knew it," McLain said at RFK Stadium. "We've lost seven games by seven points or less . . . that tells you something. A lot of things have happened here that don't happen to winning teams. It seems whenever one thing went wrong, the game plan would change or something would happen. It just wasn't a positive situation."

Coach Ray Jauch said McLain was released because he just wasn't playing very well.

"Kevin is a smart player and gave it a good effort, but he just wasn't up to par," Jauch said. "The time away from the game (3 1/2 years) took some of his speed and hitting."

McLain's departure makes a starter of rookie linebacker Mike Muller, a former all-Met player at Seneca Valley and three-year starter at Maryland.

"Mike's awful green and will make some rookie mistakes, but we'll stay with him (the remaining four games) unless something drastic happens," Jauch said. "Mike has good speed, is a hitter, and has played very well so far."

Muller, who signed a month ago, had been backing up McLain in the middle and coming in on special situations.

"I didn't exactly light up the field, but I felt I did okay in my first three games," said Muller, one of four Maryland players with the Federals. "When you don't play much, it's hard to get in the flow of the game and you look to make the big play.

"I'm getting an opportunity to start and establish myself as a player. I'm a little nervous, but I'm looking forward to it. Arizona is not your basic run-right, run-left team and it's going to be rough."

The Wranglers (4-10) defeated the Federals (1-13) in their first meeting at RFK, 22-21. In that game, quarterback Alan Risher threw a 98-yard scoring pass to Jackie Flowers, the longest play from scrimmage in USFL history. Risher is an excellent short passer and uses his backs very well. The rookie quarterback from LSU injured his ribs in a 17-13 loss to the L.A. Express last week but is expected to start Saturday night at Sun Devil Stadium.

The Federals announced that wide receiver Vince Kinney (torn knee ligaments) has been placed on injured reserve. The Federals also traded the rights to linebacker Kiki DeAyala, the 11th-round draft choice from Texas, to the Houston Gamblers for an undisclosed 1984 draft choice.