Saquon Barkley Bros Out with Baker Mayfield & Sam Darnold

Check this out ... #1, #2 and #3 all hanging together at LAX and TMZ Sports has the video!!

NY Giants rookie Saquon Barkley -- along with Baker Mayfield and Sam Darnold -- all touched down at LAX for the NFLPA Rookie Premiere event ... and they all seemed pretty stoked to reunite!

Barkley and Mayfield hugged it out ... and Saquon actually carpooled with Darnold (Jets and Giants mingling?!).

Of course, Saquon couldn't have been nicer -- complimenting his new NY rival ... even saying he's rooting for him!

We also asked Barkley about Eric Dickerson's recent comments -- that he's hoping Barkley will NOT break his rookie rushing record, and Saquon even handled that with 100% class.