The Luka Doncic trade was so big, it even got brought up during the biggest night in music ... with Jim Gaffigan making a joke about the blockbuster deal at the Grammys!!

The silly comment came early in Sunday's event at Crypto.com Arena -- which just so happens to be Luka's new home -- when coming out of a commercial break, the comedian took the mic and said Trevor Noah was no longer able to lead the show.

"During the break -- I don't know how to say this -- Trevor Noah was traded to the Dallas Mavericks," Gaffigan said.

Even though it was filled with a bunch of singers, writers and producers, some folks in the crowd got the joke ... with several people hollering in approval.

"So, I know this is a shock but I am now your host," he added.

Luka -- the face of the Mavericks franchise -- was shipped to L.A. in a jaw-dropping deal including Anthony Davis late Saturday night ... catching the entire NBA world by surprise.

Luka is just 25 years old and led the Mavs to the NBA Finals last season ... and AD is no scrub, but injuries and age certainly raise questions as to why Dallas was so quick to pull the trigger and part ways with their prized superstar so early in his career.

Regardless, Luka is now in the Purple and Gold ... and the Lakers' future is set -- that is, if he agrees to a max deal down the road.