San Francisco and Denver have the parameters of an agreement in principle on a trade for quarterback Colin Kaepernick, sources said.

But before a deal is completed, the 49ers, Broncos and Kaepernick have to agree on who will pay the quarterback's $11.9 million guaranteed salary for this upcoming season, according to a source.

The Broncos are willing to pay $7 million a source confirmed to ESPN. But Denver and Kaepernick would like the San Francisco to pay the remaining $4.9 million and the 49ers have been unwilling according to a source, believing they should not have to pay for a player they'd like to keep on their roster. Kaepernick has also been unwilling to forfeit the $4.9 million to make the deal work, according to a source.