Updated

The San Francisco 49ers have agreed to trade quarterback Alex Smith to the Kansas City Chiefs, according to multiple reports.

In return, the 49ers will reportedly receive draft picks, with one likely being a second-round selection in 2013.

The deal can't be official until the league year starts on March 12.

Smith, the 2005 No. 1 overall draft pick, lost his starting job to Colin Kaepernick last season after suffering a concussion against St. Louis on Nov. 11. He finished the 2012 campaign by completing 70.2 percent of his passes for 1,737 yards with 13 touchdowns and five interceptions in 10 games.

The 28-year-old Smith has thrown for 14,280 yards with 81 touchdowns and 63 interceptions in 80 career games.

As a result of the trade, the Chiefs are expected to cut ties with former starting quarterback Matt Cassel.