With the Chicago Bears due at the Metrodome for tonight's meeting with the Minnesota Vikings, these two players with the same first and last name were set to face off as featured running backs for their respective teams for the first time.

They aren't related, and they sport far different styles, backgrounds and accomplishments. They haven't acknowledged a lot of intrigue about their namesake, either.

If only for the sake of the NFL's unofficial brotherhood, though, Adrian Peterson of the Bears and Adrian Peterson of the Vikings have found themselves quietly cheering for the other.

"It's hard enough getting in the league, so you have to root for everybody," said the Peterson of Chicago. "There are so many different obstacles you cross to make it to the NFL, and it's only one out of, I guess, 500 who make it. Coming from childhood all the way up, I'm sure it was a dream of his to make it to the NFL, so I'm excited for him."

Any moral support, of course, was put on pause this week.

"You always want other guys to do good, too, just not when they are going against you," said the Peterson of Minnesota.

For simplicity's sake, we'll call the Vikings' rookie by his nickname, A.D., the acronym for "All Day." The Bears' version will be referred to by his actual initials, A.P.

A.P. grew up in Florida and played at Georgia Southern, where he became the all-time leading rusher in either of the NCAA's top two divisions with 6,559 career yards.

Coming from a smaller school, however, he wasn't drafted until the sixth round in 2002. Being a third-stringer behind the likes of Anthony Thomas, Thomas Jones and Cedric Benson has required him to excel on special teams, and he has been one of Chicago's best tacklers on punt and kickoff coverage. Last year, he forced two fumbles.

He rushed for 391 yards and averaged 5.1 yards per carry in 2005, but A.P.'s opportunity didn't truly come until three weeks ago when Benson hurt his ankle and was placed on injured reserve. With Jones now playing in New York after an offseason trade to the Jets, Peterson finally had the backfield to himself.

"He's a hard runner," Minnesota cornerback Antoine Winfield said. "Of course if he's made it this far, he's a pretty good player."

A.D. became nationally known by rushing for 1,925 yards in 13 games for Oklahoma in 2004. He came in second in the Heisman Trophy voting, the highest finish ever by a freshman. He left school after three seasons and, despite some concern about his durability, instantly energized the Vikings' offense when he fell to them with the seventh overall draft pick.

By then, A.P. knew all about this kid with the same name as him.

"I saw his first game, I believe. I forget who it was against, but he was killing them," A.P. said.

A.D. had discovered the irony, too.

"It's kind of weird, playing the same position and all," he said, laughing.

On Oct. 14, A.P. carried the ball just twice for the Bears. He could only watch from the sideline while A.D. embarrassed the injury-depleted Chicago defense with three touchdowns and 224 yards rushing. Three weeks later, A.D. set the NFL's single-game record with 296 yards against the San Diego Chargers.

Despite missing two weeks due to a ligament injury in his right knee, A.D. entered the weekend ranked second in the league with 1,200 yards, behind only .

"I don't know if I've played against that many rookie backs, but he would probably be the best one," Bears defensive end Alex Brown said.

Last week, A.D. had his self-declared worst game ever. The San Francisco 49ers blitzed their cornerbacks often and stuffed his 14 carries for a net total of 3 yards. A.D. professed to learn "a lot" from that performance after watching the humbling video.

"Just a lot of different things I could have done different," he said, "as far as footwork and little things like that that I could have corrected which would have changed the outcome on a couple plays."

With plenty to fix themselves from the last time they met Minnesota, the Bears were, of course, far too busy this week to worry about this trite name game involving a couple of fellows named Adrian Peterson.