The San Francisco 49ers have arguably the most important training camp of any NFL team ahead. Rarely does a Super Bowl contending team have a quarterback battle to watch, but San Francisco's eventual decision on Brock Purdy, Trey Lance, or Sam Darnold behind center could have massive ramifications both for the 49ers roster and around the league.

Will Purdy be ready to play after tearing the UCL in his elbow during the first quarter of last year's NFC Championship Game? Will Trey Lance show enough improvement after missing all but two games last year with a broken ankle? Will Sam Darnold, who is finally surrounded by elite talent, show enough in training camp and preseason to warrant serious consideration after finishing last year strong?

Perhaps above all else, should the 49ers make a trade early in training camp to provide some clarity for the rest of the roster?

Here's the case for each QB in what will be the 49ers' toughest roster decision at training camp:

Brock Purdy – The Clubhouse Leader

At least to begin training camp, Purdy appears to have the edge over his competitors. 49ers GM John Lynch said as much in an offseason interview on SiriusXM NFL Radio, via Pro Football Talk.

“Brock is the leader in the clubhouse, as we said, but it’s open for competition,” Lynch said.

Purdy will have to prove he's fully healthy, first and foremost, but it makes sense that the 49ers would lean in his direction after he went a perfect 7-0 last year as a starter. Purdy performed unbelievably well as a rookie, throwing 16 touchdowns to just 4 interceptions across the regular season and playoffs.

The picks traded to acquire Trey Lance are a sunk cost, and shouldn't factor into any future decisions. In comparison to Lance, Purdy appears to be more accurate, quicker to progress through his reads, and less of an injury risk moving forward. He earned the respect of the locker room as a leader with his inspired play last year, and he's earned the chance to start Week 1 if his elbow holds up.

Trey Lance – The Ceiling Pick

The scenario where Lance wins the starting job isn't all that far-fetched. Maybe Purdy struggles with his arm strength during the preseason or has some regression on a few of the interceptable passes that were dropped last season while Lance lights it up. Maybe head coach Kyle Shanahan opts to make his running game virtually unstoppable with the threat of Lance's legs opening up all kinds of running lanes for Christian McCaffery and company. Starting Lance could give Purdy more time to fully recover, and let the 49ers know without question whether or not Lance has the goods. Boosting his trade value wouldn't hurt, either.

It's also possible that a version of Lance who fully realizes his potential provides a higher upside than Purdy. The most dangerous quarterbacks in the league right now are mobile, and while Purdy does a nice job of extending plays, he's not the breakaway threat that Lance is.

The most dangerous version of the 49ers offense features Trey Lance behind center. The most reliable version has Brock Purdy. The 49ers have enough talent elsewhere to go the safe route, but the ceiling pick is at least worth exploring during training camp.

Hype up Lance, let him shine in the preseason, and see if any quarterback-needy teams around the league come calling and help Shanahan make the tough decision for him.

Sam Darnold – The Darkhorse

Is it a little crazy? Sure. But if the 49ers move on from Lance in a trade, and Purdy isn't quite 100 percent going into the season, it's not a crazy suggestion that Darnold could at least start the first few games for the 49ers.

While the career stats for Darnold aren't impressive (61 touchdowns to 55 interceptions), Darnold performed well as the starter down the stretch for Carolina last season when he finally had a decent combination of weapons and protection. The 49ers obviously have both of those things in spades, and so there's reason to believe that Darnold could play the best football of his career and hold down the fort while Purdy fully recovers.

The 49ers should be in championship contention with any of their three quarterbacks starting — that's how good the rest of the roster is. Identifying that starter, though, will be the top priority at training camp this season.