Colin Kaepernick Game-Worn, Signed Playoff Jersey Hits Auction, Could Fetch $40K

Niners fans looking for a pick-me-up after Sunday's brutal loss are in luck ... S.F. supporters can now nab a Colin Kaepernick jersey that the QB wore during a playoff game!!!

The threads -- which Kaepernick rocked in the NFC Divisional Round game back in the 2012 season -- just hit the block at Heritage Auctions ... and officials there tell TMZ Sports it could fetch $40,000.

Kaepernick balled out in the gear -- throwing for 263 yards and rushing for 181 more ... all while handily beating Aaron Rodgers and the Green Bay Packers, 45-31.

The scarlet and white jersey features grass stains that the signal-caller picked up while playing in the January 12, 2013 game ... and it also has his signature inscribed on the No. 7.

Kaepernick also wrote his stats on the jersey -- noting the four TDs he scored during the game.

The rare piece just hit the auction block on Monday ... and bidding is set to close on Feb. 25.