The Florida funnel opened wide yesterday as the Redskins traded for running back Benny Malone of the Miami Dolphins, signed former Miami receiver Terry Anderson as a free agent and, in a surprise move, swapped veteran wide receiver Frank Grant to Tampa Bay for an undisclosed draft choice.

The NFL's trading deadline struck at 4 p.m. and the undefeated Redskins refused to stand pat on a day of breathless and somewhat complicated behind-the-scenes maneuvering.

The trade for Malone, a fifth-year man with a 4.2-yard per gain average as a professional, also involved Buffalo Bill fullback Jim Braxton, who is now headed to the Dolphins as a result of all the wheeling and dealing.

First the Redskins sent an undisclosed draft pick to the Bills in exchange for Braxton.

They traded Braxton and another undisclosed draft choice to the Dolphins for Malone - the player they truly coveted - and another undisclosed pick.

None of the four clubs would reveal what draft choices were involved in the trades. However, it is believed the Redskins gave up betwen a second and fourth choice for Braxton and got a third-round pick from Tampa Bay for Grant. The Miami-Washington picks exchanged were believed to be in the fourth-to-sixth-round range.

"It's been a little hectic to say the least," said Redskin General Manager Bobby Beathard, who drafted Malone and Anderson for the Dolphins when he was Miami's director of player personnel. "But I think we've really upgraded the football team."

But not everyone was smiling at Redskin Park.

To make room for Anderson, a 5-foot-9, 182-pound speedster and special teamer released by Miami two weeks ago, the Redskins were forced to place reserve tight end Greg McCrary on waivers to remain at the 45-man roster limit.

The trade of Grant, a starter since 1975 and a popular player, left many teammates shaking their heads and wondering why. So did Grant.

"I thought I had been making as much of a contribution as they allowed me to make," said Grant, who had only six catches in the Redskins' first six games and dropped a touch-down pass in the season opener at New England.

"Every receiver is going to drop one now and then," he said. "And I've been open but I haven't gotten the ball. I wasn't complaining, though. Hell, we're 6-0. I kind of sensed something was wrong, but when I asked certain people, I was told everything was okay. They kept saying I was doing a good job.

"To come this far and to have this happen to you kind of upsets you. I could see it if I wasn't performing, if I was screwing up a lot and not doing it. But on the grade sheet the last three weeks, I've gotten 100 percent.

"Right now, I'm just confused. I'd rather stay, but there's nothing I can do. I'll go down there and do the best I can."

Redskin Coach Jack Pardee hinted at the reason for Grant's trade when he said. "With all these moves, we think we've improved our team speed, and particularly our receiver speed. And I know what receiver does to you defensively, particularly with some of the new rules.You can't hit the receivers down field any more, so little guys can catch passes like big guys. You just have to have speed."

That is one reason the Redskins have been interested in Malone "for quite some time now," according to Beathard.

Malone 5.10, 193-pounder drafted out of Arizona State in the second round in 1974, has had eight 100-yard games in four seasons in Maimi. There have been reports that he had fallen out of disfavor with Dolphin Coach Don Shula, but Beathard insisted, "That's just not true."

"Benny just feels he should have played more, but he's been a real man about it.He's been playing on all their special teams and he's a great competitor. He's a real tough, fast, exciting runner with an unorthodox, hell-bent-for-leather style. He also has amazing strength."

He also has a sprained ankle from Miami's 21-0 victory over Cincinnati Monday night. Beathard said Malone probably would not be ready to play for another week, "but it's not a real serious thing at all."

Malone had been the Dolphins' special teams captain in four of six 1978 games. But he had carried the ball only six times for 18 yards.

"I don't know what his problem was down there," said Pardee, "but the way Miami is using Delvin Williams (the AFC's leading rusher), it's hard to second-guess that. No, I don't think Benny is any kind of chronic fumbler; that's just something you hear on television."

Pardee said he thought Malone could play at either fullback or tailback and probably will be asked to learn both positions.

And while Pardee said otherwise, another factor in the aquisition of Malone may well be the fact that starting tailback Mike Thomas is playing out his option this year. Malone adds a bit of insurance.

"I'm not worried about next year," pardee insisted. "I'm just concerned about how we can keep winning. You try to upgrade any time you can. The said part is having to turn loose a player like Frank Grant, but that's better than some other alternatives."

One alternative could have involved wide receiver Danny Buggs, who separated a shoulder against the Jets three weeks ago and probably will not be available against the Eagles this week.

"We could have put him (Buggs) on injured reserve," Pardee said, "but we decided to wait. I think Danny can help us win some games down the line."

With John McDaniel and Ricky Thompson having played well the last two weeks, and yesterday's addition of Anderson, Grant became expendable.

Anderson, a second-year pro from Bethune Cookman drafted in the 12th round by Miami in 1977, played in 11 games as a rookie in 1977 and returned seven kickoffs for a 23.9-yard average.

He played in four games this season before being waived when Miami needed to protect several injured defensive players. Pardee described him as an excellent special teams player and, if Buggs is not available against the Eagles, Anderson may see some action as a receiver this week.

Pardee said he hoped the trade of Grant would not have an adverse emotional affect on his team.

"I hope everyone will accept it for the reason it was done - so that we'll all have a chance to be more successful," he said. "I think we've made the moves today that are going to be a great help all the way down the line. We think we covered ourselves at our vulnerable spots."