Gene Upshaw, executive director of the National Football League Players Association, expressed concern yesterday that eight of the 32 players serving as union representatives have been released by NFL teams this season, including nearly half of the players on the union's nine-man executive committee.

Upshaw said that becoming a union representative "cuts two years off a player's career."

He added, "It's become a joke around the league that if you're a player rep then you are on the hot seat and your career is cut short."

Four members of the executive committee were released by various NFL teams this season: the union's president, Tom Condon (guard, Kansas City); the first vice president, Mark Murphy (safety, Washington Redskins); at-large member Billy Shields (tackle, San Francisco) and alternate Amos Fowler (running back, Detroit).

The other player representatives who were cut this season are linebacker Dick Ambrose (Cleveland), kick returner Carl Roaches (Houston), safety Ron Johnson (Pittsburgh) and linebacker Chris Keating (Buffalo).

Three of the eight union representatives signed with new teams. Keating was signed by the Redskins Tuesday and earlier Condon signed with New England and Shields with the New York Jets.

A fifth member of the executive committee, Minnesota wide receiver Sam McCullum, 32, retired prior to last season. McCullum had filed a grievance against Seattle before retiring, charging that the reason the Seahawks had released him in 1982 was because he was a union representative.

An administrative law judge of the National Labor Relations Board sided with McCullum, an 11-year veteran. The NFL still awaits the decision of its appeal to the NLRB's five-member appeals' board, an official of the NFL Management Council said yesterday.

Jim Miller, director of administration of the Management Council, said in response to Upshaw, "They are stretching for an argument. They have just decided to tie everything up and put a little ribbon on it. It is a known fact that older players are player reps. It's also a known fact that older players get cut a lot of the time.

"You could probably take the average length of career of those eight guys and it would be well above the average length of an NFL player's career, which is 4.5 years."

In fact, the average age of the eight union representatives who were cut this season is 30, with an average league service of nearly nine years. Ambrose, Condon and Shields are 32 and Roaches is 31. The other four players -- Murphy, Johnson, Fowler and Keating -- are all 30 or younger.

"All of these things don't just happen out of the clear blue," Upshaw said. "Squad sizes are being reduced, the contract sizes are going down, we've seen more holdouts than before. There has been an attack on player leadership. What I've suggested to the players is that (NFL) management is showing us they are getting ready for bargaining." (The current collective bargaining agreement between players and management expires after the 1986 season.)

Miller said that he doesn't agree with Upshaw's contention that becoming a union representative shortens a player's career. "It sure didn't hurt Billy Shields (11 seasons of service). It sure didn't hurt Tom Condon (12 years of service), either. I just don't think that's accurate."

NFL teams voted this week to choose new player representatives. Members of the NFLPA's executive committee, chosen prior to the 1984 season, will continue to serve until their two-year term ends prior to the 1986 season.

Upshaw said he hopes to gain some form of protection for player representatives in the future. He would like to put such protection in the next collective bargaining agreement, he said. If no protection is obtained, Upshaw said, "there won't be any players who will be willing to take the risk (of becoming a union representative) in the future."