Four games. That's all it took for Boise State quarterback Joe Southwick to transition from embattled to entrenched.

Now his coach wants to see what the senior can do with eighth months of offseason as the Broncos football team opens spring practice Monday.

"I want him to maintain his improvement that he's done," quarterbacks coach Jonathan Smith said a month ago. "I really felt like he improved from beginning to end and if he can keep on that same plane of improvement we'll be really, really excited about him. He's already watching film, getting right. The guy doesn't stop. So I've got no hesitation that Joe will continue to improve."

Southwick was 79-of-113 (69.9 percent) for 888 yards and nine TDs with no interceptions in the final four games last season. He also rushed for career highs in each of the last two games.

He had 10 TDs and seven interceptions in the first nine games, including two in which the Broncos didn't score an offensive TD.

"There was something that triggered him," Smith said. "Some of it was he recognized he could be a threat with his feet. He's not Michael Vick, but it expands his game when he can take off. So I think that was huge. And I think he got more and more confident and comfortable. We can say what we want - he stepped into some huge shoes (replacing Kellen Moore) and an arena that was brutal and that's going to take a minute to get over that stuff.

"And he did. And he kept battling. That's what I love about the kid - he's so tough."

Southwick hasn't been made available to the media since the MAACO Bowl Las Vegas. That day - after leading a game-winning drive against Washington - he credited a season-long progression for his late-season surge.

"All year, I've known I could play at this level," he said. "It's just a lot of work, a lot of moving parts, to fit the puzzle together. The last three or four games, it's really showed. We've been executing at a higher level on offense."

Smith said he's glad coaches stuck with Southwick through some difficult times. They never seriously considered a change, he said.

"His preparation, we just felt like he was going to get better, and he did - to his credit," Smith said. "I think he's got a chance to be really good next year. If he keeps going about it the way he does, has a good spring and fall camp, I think he'll be a good quarterback."

Southwick should benefit from the return of offensive coordinator Robert Prince and Smith, who were in new roles last year. Prince, in fact, was the third coordinator in as many years.

Southwick also has the bulk of his receiving corps back.

"It's definitely been better on us and him," senior wide receiver Kirby Moore said of having an established starter. "We've been working a lot - throwing after (workouts) and watching film together on things we could have maybe done better during the season."

Behind Southwick, three quarterbacks will compete for the backup job and, coaches hope, force Southwick to improve to hold his job.

"I do want him to feel a little push from the younger guys because I think there's some talent there behind him," Smith said. "And that's what spring ball is all about. Those guys are going to get some turns to see where we can progress as a group but also each guy individually."

Chadd Cripe: 377-6398, Twitter: @IDS_BroncoBeat