While a player with Brady's resume missing voluntary OTAs shouldn't set the world on fire, it should be noted that the 40-year-old has been a frequent participant in the past.
The three-time NFL Most Valuable Player committed to play the 2018 season during an appearance April 30 at the Milken Institute Global Conference in Santa Monica, Calif.
Brady said at that conference that he desired to spend more time with his family this offseason while still preparing for the 2018 season.
"Part of this offseason for me is certainly about still preparing for what's ahead in my next journey, my next mountain to climb with this group of teammates, but it's also [acknowledging] that a lot of people are getting the short end of the stick in my life -- certainly my wife and my kids," Brady said at the time.
"Football is year-round for me. It's a lot of thought, a lot of energy and emotion put into it, but I need to invest in them, too. My kids are 10, 8 and 5. They're not getting younger, so I need to take time so I can be available to them, too. ... I've really spent the last two or three months doing those things, and I think I'm really trying to fill my tank up so that when I do go back, I can go back and I think I'll actually be, in my mind, a better player, a better teammate, because I'll be really rejuvenated."
Per the Boston Globe, Brady has been seen training both on the beach and on the field at UCLA. The newspaper also reported that he is expected to invite Patriots wide receiver Julian Edelman and tight end Rob Gronkowski to Montana for additional workouts in July.
NFL Network Insider Ian Rapoport reported that Brady is expected to participate in the mandatory minicamp, which is slated for June 5-7.
Brady has two years remaining on his contract and is currently scheduled to earn a base salary of $14 million in 2018.
He threw for a league-best 4,577 yards and 32 touchdowns with only eight interceptions last season.
Brady is the oldest player to receive the NFL MVP award and the fourth to win it three or more times (Peyton Manning, five; Brett Favre and Johnny Unitas, three apiece). Brady was also the NFL MVP after the 2007 and 2010 seasons.