Joe Montana had probably his best season in 1987, when he won his first NFL passing title, threw a league-leading 31 touchdown passes, set a league record with 22 consecutive completions and led the 49ers to a 13-2 record.

Despite all that - and Super Bowl titles under his direction in 1981 and 1984 - Montana may not be San Francisco's starting quarterback when the 49ers open Sept. 4 at New Orleans.Ever since the 49ers' 36-24 playoff loss to Minnesota Jan. 9, the quarterback situation has been a subject of controversy in San Francisco. Some insist Montana should remain the starter. Others maintain flashy newcomer Steve Young should replace him.

With the 49ers set to begin their exhibition season here today against the Dolphins, interest is growing stronger and the competition more heated.

Montana will start today, but he'll have to prove he deserves the job to retain it.

Waiting for him to falter is an impatient Young.

"I've learned a lot from Joe, but I think I'm at a point now where I need to play to get any better," Young said.

"Joe's the starter, so I've got to beat him out. Joe's been All-Pro and all-everything for a long time. I have a lot to do, but I'd like to think I could beat him out."

Several factors may be working for Young and against Montana, who is 32, had off-season elbow surgery and has a chronic back problem. More importantly, Montana was ineffective in the playoff loss and was replaced by Young, whose spectacular play fueled the ensuing controversy.

Young, 26, is an exceptional athlete who can run and pass with equal efficiency.

He played well when given the opportunity last season, throwing 10 touchdowns passes and no interceptions, but he didn't emerge as a threat to Montana's job until his performance against the Vikings.

Young had replaced Montana early in the third quarter with San Francisco trailing 27-10.

Young rallied the 49ers, completing 12 of 17 passes for 158 yards and a touchdown. He also rushed for a team-leading 72 yards and scored on a 5-yard run.

"That game made all the difference in the world for me," Young said. "I'm very confident.

"I feel I just want to play, and I want to play a lot. I feel like I want to get into a game and make things happen."

After the season, coach Bill Walsh said the quarterback job was wide open but has since backed off.

Montana has the starting job until further notice - or further ineffectiveness.

"Joe last year was the premier quarterback, but when Steve had an opportunity to play, he was a very exciting and explosive performer," Walsh said. "Steve is so charismatic and exciting that he can actually push Joe for the job. And if Montana were to unfortunately stumble, Steve would be there to pick up the pieces."

Benching Montana won't be easy. His career efficiency rating of 92.5 ranks second all-time behind Dan Marino's 94.1.

He has been the Super Bowl MVP twice, voted the NFC's Pro Bowl starter three times and is a future Hall-of-Famer.

Since becoming the starter late in 1980, Montana had never been taken out of a game whose outcome was in doubt - until the Minnesota loss. He was sacked four times, threw an interception that was returned for a touchdown, and completed 12 of 26 passes for 109 yards.

Montana was unhappy about being yanked but said he wasn't shaken by the decision. He said he reported to camp in the best shape of his nine-year career and is prepared to pick up where he left off in the regular season.

"I'm still very confident in myself," he said. "I've been in this league for 10 years, and I've seen better teams than ours lose, and I can go down the string of all quarterbacks in the NFL who have been pulled from a game. I just have to feel that it's taken me 10 years before I've been pulled. When I look back on it, it's happened to everybody.

"Nobody likes it, but that's the way it goes."

It cost San Francisco a second- and a fourth-round draft choice to acquire Montana's competition from Tampa Bay four days before the 1987 draft.

Young spent two seasons with the Buccaneers after beginning his pro career in the USFL.

His Tampa Bay days were hardly memorable. The Bucs were awful and Young was ill suited for Leeman Bennett's stay-in-the-pocket offense. He had 21 interceptions and 10 touchdown passes in 19 starts, but he did lead the league in passing attempts and completions in 1986.

Despite his inconsistency and the Bucs' problems, Young said he was always confident he could become a top-flight quarterback. All he needed, he said, was an opportunity to play with a winner.

"Even when we were getting our butts kicked in Tampa, I felt there was some good football being played, and I felt I was getting better," Young said. "I could feel it. It didn't show, but I was getting better."

Now it's just a question of whether he's better than Montana.