MOBILE, Ala. — The 2019 Senior Bowl gets underway with a big day on Tuesday, with players from both teams weighing in officially, conducting Media Day interviews at lunchtime and then putting the pads back on for a pair of practices that afternoon.

The two squads comprised of 114 seniors — and eligible juniors who have completed their degrees — will be coached by Jon Gruden and the Oakland Raiders (North Team) and Kyle Shanahan and his San Francisco 49ers staff (South Team).

There had actually been nine quarterbacks at the game before Northwestern's Clayton Thorson bowed out because of an injury. The four QBs coached by the Raiders include Missouri’s Drew Lock, Duke’s Daniel Jones, Penn State’s Trace McSorley and North Carolina State’s Ryan Finley. The QBs on the 49ers-led South team are: West Virginia’s Will Grier, Washington State’s Gardner Minshew, Auburn’s Jarrett Stidham and Buffalo’s Tyree Jackson.

[PFW Podcast 127: A Senior Bowl special — Ryan Leaf helps break down some of the top Pac-12 prospects and Gabe DeArmond talks about Mizzou's Drew Lock]

Jackson was the final quarterback added to the roster in the past few weeks after he decided against changing schools as a graduate transfer and instead opted to declare for the draft. New Senior Bowl director Jim Nagy, who took over this year for Phil Savage, said Monday that they decided to add Jackson to “get the best players to Mobile,” which should make NFL scouts happy.

Hundreds of scouts are here to spy the talent across the board at every position, and it appears to be a strong crop — even with the highest-rated prospect who initially had committed to play in the game, Kentucky edge rusher Josh Allen, deciding last week not to attend. The reason: He’s roundly viewed as a top-10 cinch, and he likely had little to gain from a week’s worth of workouts.

Of course, Baker Mayfield played in the game last year, and Nagy told PFW earlier this season that he believes it was that decision that helped vault him into consideration for the No. 1 overall pick. The Cleveland Browns used that pick on Mayfield, which now looks like a stroke of genius. Another top-10 quarterback, Josh Allen, also played in last year’s game and “got better every day,” Nagy said, which led to the Buffalo Bills trading up to the No. 7 overall pick to select Allen.

Is there a Mayfield or Allen in this year’s group? It’s hard to say. But Lock and Jones figure to have the best shot, even with others making it an intriguing bunch overall.

Lock spoke Monday night about his decision to return to school for his senior season, having “zero regrets” about that and how he looked forward to improving his stock this week on the practice fields.

“I am 10 times more prepared now than I was before,” Lock said. “I want to go into these meetings and wow everybody that I talk to. Had I come out as a junior, I don’t think it would have been up to the standard I wanted it to be.”

Of course, it’s not just about the quarterbacks. Nagy said he believed NFL scouts were most excited about the offensive line group this week, and it won’t hurt that Allen and a few other pass rushers bowed out of the game after committing. Washington State OT Andre Dillard might be the most anticipated Senior Bowl performer up front, but there is a nice group also highlighted by Kansas State’s Dalton Risner (a “four-position player,” Nagy said, indicating he could play almost anywhere but left tackle), Washington’s Kaleb McGary, Mississippi State’s Elgton Jenkins and Wisconsin’s Michael Deiter are just a few other top blockers set to perform here.

But even without Allen, the pass rushers are interesting. Mississippi State’s Montez Sweat might have the most to gain — or lose — among the group this week, starting with the weigh-in. If he’s closer to the 240-pound range some scouts fear, it could hurt Sweat; if he comes in over 250, that’s likely to please scouts more.

Another pass rusher we’ll be keeping a close eye on: Old Dominion’s Oshane Ximines, who could be a fast riser. Ximines easily can shed the small-school tag with a good week in one-on-one drills, just as UTSA’s Marcus Davenport did last season. Although Nagy pointed out that Davenport was “up and down” during the week of practice, he peaked with a huge performance in the game itself at the end of the week and ended up a first-round pick of the New Orleans Saints, who traded their 2019 first-round selection to ensure getting him.

There are plenty of other big-name prospects and sleepers we’ll be watching and writing about throughout the week. The biggest concern right now might be the weather, as heavy rain is expected on Wednesday and could move practices indoors on the University of South Alabama’s campus.

But come rain or shine we’ll do our best to bring you and highs, lows and sights from the Senior Bowl practices every day through Thursday in what annually is one of the best pre-draft events that can make or break some prospects’ draft stocks depending on how they perform.