Ask the Redskins the motive behind George Allen's latest surprise, the rehiring of veteran safety Brig Owens, and most shrug their shoulders and reply, "Who knows?"

"Don't ask me to explain the man upstairs," one veteran pleaded, "because I can't."

The theories will fly fast and furious in the next few days, although Allen's latest decision was a popular one at Redskin Park. It was learned that some black players were upset last week when Allen re-signed Jerry Smith, claiming he needed the tight end to provide leadership for the team. If so, said some, then Owens should have been brought back with Smith.

It also was learned that several black players expressed their displeasure to team officials over what they saw as a slight to Owens. Allen denied that yesterday, insisting, "No one ever mentioned it to me, not one person. This was strictly my own decision."

Anyone familiar with the inner workings of professional sports should not be surprised at reports there still are black-white divisions, even on the Redskins, a team that constantly tells the outside world "we are together."

It is unlikely the Redskins will be split by racial problems, although several players say there is the same black-white division on the Redskins as on most other teams. Most black players stay together. So do the whites.

And there is another split among the Redskins: the young versus the old. It is known, for example, that a number of the veterans on the team still question the determination and loyalty of third-year running back Mike Thomas.

Their doubts go back to the 1975 season, when Thomas, then a rookie, missed several games with what some older players say were minor injuries. They say he could have played, and should have because the team needed him.

The same group was upset that Thomas missed all of the 1977 training camp with a pulled hamstring muscle. His signing a $100,000-plus contract halfway through the summer caused some resentment, too, particularly among several veterans who are having difficulty with their negotiations.

We practice every day, they grumbled. Why can't he?

Another issue very much on the minds of the players is the continuing quarterback controversy.This, too, is a classic confrontation between young and old.

Some younger players wonder how much longer Allen will stick with Billy Kilmer, his game but banged-up quarter back.

No one on the Redskins questions Kilmer's heart or his courage. But his performances the first two games of the season have left grave doubts about his ability to function successfully for an entire year.

Said one club official who asked not to be quoted by name, "I love the guy, and I never want to say anything about him, but I think this St. Louis game is going to be pivotal for Billy. If he has a good game, if he plays better than he has been playing, he'll be the man. If not, George has another tough decision."

Redskin players always insist publicly that it makes no difference who is quarterbacking. But the people who have to catch passes say privately that they prefer Joe Theismann's fast balls to Kilmer's floaters, for the simple reason that a zipped pass makes it more difficult for defenders to come in and knock receiver's head off.

But there also are people who still wonder about Theismann. They would like to believe that, after four years, he has matured enough to follow Allen's grind-it-out offensive philosophy.

But also they point to the half-dozen interceptions he threw in preseason games and the occasional reckless streak that makes him do strange things at just the wrong time. The classic example, of course, is the interception last year against the Giants in the Meadowlands, a blunder that nearly ruined the Redskin season.

Theismann's remark to a gathering of fans Monday night, when he expressed displeasure over his back-up role, surely was interpreted as another example of his immaturity by the veteran function on the team, even though, Theismann publicly apologized yesterday.

Still, the same group of veterans had to be gratified by Allen's decision to bring Owens back into the fold. Clearly, when he and Smith were cut two weeks ago, every player over the age of 30 had to ask himself, "If Allen could let those two guys go, am I next?" Was that the payback for all those years of loyalty?

Yesterday, Allen, went a long way toward reassuring some of the doubters, and maybe even gave himself a big lift as well. That is what Bobby Mitchell, Allen's director of pro scouting, believes was really behind the Smith Owens move.

"It's not black or white, it's not young or old," Mitchell said. "When things are tough, George wants his veterans. That's my opinion.

"From a personnel point of view, sure I want to see some of the kids make the team. But if they don't fit in, and George feels more relaxed the other way, we should not be in a position to force him into accepting anything else.

"Having Jerry there last week was important to George. You know these guys aren't going to go out there and single handedly win a football game. But they will relax George. And if he feels better, then the team is going to feel better.

"So I can't tell you why. I can just tell you he makes the decisions, and he always will. And that's how it should be."