San Francisco 49ers general manager Trent Baalke has warned the rest of the NFL of a blossoming relationship between quarterback Colin Kaepernick and pass rusher Reggie Bush.

The 49ers had a poor 2014 season and were criticised for their underwhelming passing game. They snapped up Bush two months ago and Baalke is encouraged by his relationship with Kaepernick.

He told SiriusXM NFL Radio: "Reggie has really been an asset to Colin and has opened up some things. When you get the speed going down the field and you give a back like Reggie room to work in the third-down packages and stuff like that, it really is a bonus for the quarterback. And Colin is developing a real rapport with Reggie coming out of the backfield."

The 49ers open their 2015 campaign against the Minnesota Vikings.