As expected, National Football League owners voted today to reduce the size of teams' rosters from 49 players to 45 for the upcoming season.

The move will lop 112 players from league rosters and is seen, above all, as a cost-cutting measure, each team saving an estimated $600,000 to $800,000 per year. The brunt of the reduction is expected to be felt by special-teams players, role players and younger players in general, who might not be afforded an opportunity to stay on a roster while developing.

Al Davis, managing general partner of the Los Angeles Raiders, appeared enraged by today's vote, from which he, symbolically, abstained. After the vote at a hotel in this Chicago suburb, Davis stood outside the meeting room and told a group of reporters, "Somebody stood up during the meeting and said, 'When economic times are hard, you cut your costs.' I stood up and said 'Yeah, but you don't cut your product.' How can you drop from 49 to 45 in a cavalier manner?"

Davis even appeared angry at Commissioner Pete Rozelle, who doesn't vote on such matters. "I'm a little amazed at him for not stepping in," Davis said.

"I think this is terrible. You have a lot of young players who you might not be able to develop now," said Washington Redskins General Manager Bobby Beathard, a staunch supporter of the 49-man roster. "With all of the injuries we had last year, I don't know if we could have gotten by with less than 49 players."

But Mike Lynn, Minnesota's general manager, said, "The NFL had its best season in 1981, in terms of TV ratings and attendance, and we had 45-man rosters then . . . I think it's a better game with 45."

The move seemed to indicate that the NFL owners are not as fearful of losing players to the U.S. Football League as they had been in the past three years, when they voted each time for 49-player rosters. (NFL owners will hear an update from the league general counsel Thursday on the USFL's $1.32 billion antitrust suit aimed at enjoining the NFL from appearing on more than two of the three major networks.)

Rozelle said of today's vote, "I don't think the U.S. Football League had anything to do with it . . . We talked about a lot of compromises. We reiterated the arguments we've used over the last three years.

"Those that say 49 say we'd have a better game. Those who are perhaps the weaker clubs that would get priority on (claiming other team's) cuts and waivers also felt, with the economics crunch, that we'd be better at 45."

Nineteen of the 28 NFL teams voted for the 45-player limit. The collective bargaining agreement specifies 45 players but, each of the last three poststrike seasons, owners voted for 49. Twenty-one votes are required for the move up to 49.

"I'm very disappointed. I think it's a tragic mistake," said Tex Schramm, Dallas Cowboys president.

"The last four people you keep won't make or break your team," said Billy Sullivan, president of the New England Patriots, who voted for 45. "And by keeping four less you're not shortchanging your fans."

Several compromises were offered today, including a 46-man roster (introduced by Cleveland Browns owner Art Modell) and a 47-man roster with an additional three players who would be able to practice but not play in games for two years (proposed by Davis).

"I'm worried about the quality of preparation," Davis said.

League rules stipulate that only active players and those on injured reserve who have already been inactive for four weeks may participate in a team's practice.

The sides were clearly defined today: eight teams voted for a 49-man roster and six of those were in the 1984 playoffs.

"The stronger teams want to keep what they have and the weaker teams want to cut costs," said Modell, who voted for 45.

Modell also insisted that the smaller roster had no relation to the current instability of the USFL.

"These are players that are rejects," he said.