As Team USA training camp gets underway, Boston Celtics fans get a sneak peek at their 2019 squad.

"Team Shamrock" --  a.k.a. Kemba Walker, Jayson Tatum, Jaylen Brown, and Marcus Smart -- put in some work with one another on Monday. In a video tweeted out by the NBA, the four C's stars participated in a drill together that included both Walker and Brown draining jumpers.

Watch below:

NBC Sports Boston's own Chris Forsberg captured a pair of videos of Team USA scrimmaging, and Kemba appears to be in midseason form:

Get excited, Celtics fans.

Walker can be considered a lock for one of USA Basketball's 12 roster spots, but Tatum, Brown, and Smart will have some competition. Utah Jazz' Donovan Mitchell, Milwaukee Bucks' Khris Middleton, and Sacramento Kings' Harrison Barnes also will be battling for wing spots.

The FIBA World Cup in China begins Aug. 31.

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