The Patriots won’t report to training camp for another two and a half weeks, but Tom Brady is already hard at work with a familiar face.

Brady threw to Rob Gronkowski during a private workout Monday on the UCLA campus, a source told MassLive. Gronkowski retired in March after a nine-year career in New England that should one day land him in the Pro Football Hall of Fame. The former All-Pro tight end is in Los Angeles for the second annual Monster Energy $50K Charity Challenge Celebrity Basketball Game set to tip off at UCLA’s Pauley Pavilion on Monday night.

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Gronkowski, 30, told The Rich Eisen Show last week he’s enjoying retirement, but said, “I can’t really say how I’m going to feel about it when the games start rolling around and everything.”

Brady’s personal trainer and business partner, Alex Guerrero, was also present for the private session. Brady stopped at the campus for a workout on May 1 and threw to members of the Bruins football team.

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The night Gronkowski announced his retirement, Brady posted a lengthy tribute to his tight end on Instagram that began, “What an honor and privilege to play with you these past nine years @gronk!” A week later, Brady joked in an Instagram comment he hoped Gronkowski’s career would continue.

Gronkowski caught 522 passes for 7,861 receiving yards and 79 touchdowns over 115 regular-season games in New England. He made five Pro Bowls, earned four first-team All-Pro nods and three Super Bowl rings.

Asked in June how the Pats will replace Gronkowski, Brady lauded the tight ends currently vying to fill his vacated starting spot.

“I think like any season, things are different, and we’re going to have to adjust differently and teams are going to play us differently without him,” Brady said. “We’ve seen it even when he’s been on the team. The other guys are getting up to speed; Matt [LaCosse]’s done a good job, Ben [Watson]’s done a good job, Stephen Anderson’s done a good job.”

Brady and the Patriots will report to training camp in Foxborough on July 25.