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 TMZ 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.