Brett Favre has been a bit of a good luck charm for the Kansas City Chiefs — they’re 2-0 when he’s attended their recent Super Bowls — but he can’t make it to the big game this weekend … and now, he’s hoping that doesn’t jinx Patrick Mahomes and Co.

The NFL legend tells 360Aproko Sports … because of his close relationship with Andy Reid, he’s previously gone out to two of K.C.’s three most recent SB appearances to give a championship pep talk to the team.

Both times, he said, they won … so, naturally, Reid invited him out to Las Vegas this week to keep the streak going.

However, Favre says he’s not going to be able to be in attendance this year — and he’s nervous about the juju it might bring to Chiefs Kingdom.

“Knock on wood!” the ex-Packers quarterback said.

Superstitions aside, Favre tells us he’s super proud of what Reid has accomplished since the two worked together in Green Bay way back in the 1990s … telling us he could see even then that Reid had this in him.

In fact, he says he’s never seen Andy happier … and he can’t fathom Big Red retiring after Sunday no matter what happens against the 49ers.

“He’s enjoying — maybe more so than any other time in his career — what he’s doing,” Favre said. “He seems to be in a really good place.”

While it seems Favre will be in KC’s corner by the time kickoff rolls around at Allegiant Stadium … he did offer some big praise for Brock Purdy too — and he even had some words of advice for the young Niners QB heading into the game as well.