A pretty good crowd showed up in San Diego to watch Johnny Manziel throw at his pro day. (0:21)

FOXBOROUGH, Mass. -- Coach Bill Belichick and director of player personnel Nick Caserio were at Ohio State’s pro day on Thursday, but that wasn’t the only place the New England Patriots were monitoring. One of the more intriguing developments came at the University of San Diego, where area scout Jonathan Howard was keeping a close eye on the proceedings.

In many ways, it was standard operating procedure for Howard and the Patriots, who were one of 13 NFL teams on hand to gather more information on players such as receiver Justin Priest and tight end Ross Dwelley.

But the presence of quarterback Johnny Manziel, who was invited by Priest and Dwelley to throw to them, created more buzz than the norm.

It also sparks a question: Would the Patriots, who have 40-year-old Tom Brady and 32-year-old Brian Hoyer on the depth chart, ever consider Manziel?

It would be a big upset based on how far Manziel has fallen and because the team didn’t seem to have a favorable report on him coming out of Texas A&M in 2014. But acknowledging that the only thing predictable about Belichick and his staff is unpredictability, let’s look a bit deeper at both sides of the ledger.

Why it won’t happen

Belichick has said in the past that when a team brings on a player, it gets everything that comes with the player -- on and off the field.

This year’s draft class at the quarterback position is deeper than the norm, so that is the most likely avenue for them to pursue. Safer, too.

Accuracy and decision-making are two of the traits the Patriots value most at quarterback, and they haven’t traditionally been Manziel's strengths.

He hasn’t played in two years and there are better developmental options. In the end: too risky.

Why it could happen

They once signed Tim Tebow, who brought with him a whole other level of attention as a No. 3 quarterback. If they were willing to do it with Tebow, why not Manziel?

Belichick often thinks outside the box (e.g., the Super Bowl and Malcolm Butler).

The Patriots have 10 former first-round picks on their roster (seven of whom entered the NFL with other teams), as they traditionally target players with unique traits, and pedigree. Manziel checks that box.

If he truly is committed, the presence of a former first-round pick trying to work his way up from the bottom of the barrel could be a positive add to the locker room dynamic. And again, the quarterback room in New England is short on a third option right now.