Center Erik McCoy holds the ball in position during the second day of Saints rookie minicamp at the Saints practice facility in Metairie, La., Saturday, May 11, 2019.

The New Orleans Saints begin their organized training activities (OTAs) on Tuesday. It's the first time the team's rookies and veterans will all be together. Here is a look at five things to watch for in OTAs:

5 things to watch for in OTAs

Who is playing center?

The Saints signed veteran Nick Easton in free agency. And they drafted Erik McCoy out of Texas A&M in the second round. Which one of those two will play center and replace the retired Max Unger? It is perhaps the most intriguing battle heading into the season.

The D-line shuffle

Defensive end Alex Okafor is gone to Kansas City. Defensive tackle Tyeler Davison is now with the Falcons. And defensive tackle Sheldon Rankins is still recovering from a torn Achilles tendon. So who's up front to join Cam Jordan and David Onyemata? The Saints signed DT Malcom Brown and DT/DE Mario Edwards in free agency, and those two may be counted on heavily right away. Edwards, Marcus Davenport, Trey Hendrickson and some undrafted players will have to man the defensive end position opposite Jordan. Taylor Stallworth is one of the returning tackles. 

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Jared Cook

Many eyes will be on the biggest name the Saints acquired in free agency. The tight end position hasn't been as productive the past two seasons as it typically is in Sean Payton's offense. But Cook, coming off a Pro Bowl season, could change that and make the position what it was in the Jimmy Graham days.

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Helping out Mike

Plenty was written last season about Michael Thomas having to carry the bulk of the load. But will someone emerge as another threat? The addition of Cook and a healthy Ted Ginn Jr. should help with that. But which of the other players (Tre'Quan Smith, Keith Kirkwood, Cameron Meredith or Austin Carr) will step up?

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Undrafted stars

For the past three seasons, at least one undrafted free agent has made his way onto the roster. Will there be another one this year who impresses enough to steal a spot on what appears to be an already stacked roster? David Simmons, Lil'Jordan Humphrey and Corbin Kaufusi are among those hoping to be the next to do so. 

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Follow Rod Walker on Twitter, @rwalkeradvocate.