The only two 9-1 teams in the National Football League play each other here Sunday when the Devner Broncos take on the Baltimore Colts (WBAL-TV-11, 4 p.m.).

For Denver coach Red Miller, 1977 has been a year of pressure. He took over a dissension-ridden team that still had managed in 1976 to post a 9-5 record, best in the history of the franchise. Miller already has matched that victory total, and if the Broncos manage to win three of their last four games they will unseat the Oakland Raiders as champions in the AFC West.

If miller has relieved the pressure to equal last season's mark, he still is challenged to explain his selection of Craig Morton, who left few wet eyes in Dallas and New York, to quarterback the Broncos.

"Morton has what you cannot get with draft choices or money, experience," Miller said. "Experience and leadership.

Leadership? . . .

"Yes, leadership. I let the players vote for offense and defense captains. Morton won overwhelmingly. We thought Craig would be a good quarterback if we surrounded him with talent."

Morton will be put to the test by the Sack Pack of the Colts, but so far he has made Miller look like a wily horse trader for dealing off Steve Ramsey to the Giants in exchange for Morton. Ramesy was cut by the Giants before the season began.

Miller admitted he considered other quarterbacks while negotiating for Morton but said. "He was the best of those we weighed."

Craig Penrose was thought to be a sure bet to be the Broncos quarterback in training camp, even though Miller said he would not decide on a starter until the fourth exhibition game. Morton got the nod.

Morton was intercepted 20 times last season with the Giants. Through the first 10 games this year, his throws have been picked off only six times.

Having split two games with Oakland, and ending up with a better point differential in case of a tie in the standings, the Broncos Sunday face another quarterback rated among the very best Bert Jones. If the Denver defense can stop him a play off berth almost would be assured.

The Broncos next play at Houston the San Diego here and close out the regular season at Dallas.

In an intersectional and interconference game, the Los Angeles Rams (7-3), leaders in the NFC west take on the Browns (6-4), co-leaders in the AFC central, at Cleveland.

While the Rams have a two-game lead over Atlanta (5-5), the Browns are tired with Pittsburgh and Cincinnati and Houston are only a game back with 5-5 records.

Pittsburgh plays the Jets (2-8) at New York, the Bengals oppose the Giants (4-6) at Cincannati, and the Oilers host Kansas City (2-8).

Defending Super Bowl champion Oakland a game back of the Broncos in the AFC West at 8-2, is at home against Buffalo (2-8) Monday night.

The Falcons will try to stay within reach of the Rams and keep alive hopes for a wild-card berth in their game against the Buccaneers (0-10) at Tampa Bay.

The Patriots (6-4), who were supposed to be a strong contender in the AFC East with the easiest schedule in the league, will be endeavoring to stay within reach of the Colts and Miami (8-3) in case those teams falter. The Patriots play the Philadelphia Eagies (3-7) at Foxboro, Mass.