49ers sign quarterback Thad Lewis to one-year deal

The San Francisco 49ers signed quarterback Thad Lewis to a one-year contract on Thursday as speculation mounts about Colin Kaepernick's future with the team.

Sources told ESPN's Adam Schefter on Thursday that the Denver Broncos, New York Jets and Cleveland Browns had expressed interest in trading for Kaepernick, although no trade was imminent.

Kaepernick's agents asked the 49ers for permission to seek a trade last month.

Lewis becomes the fourth quarterback on the 49ers roster, along with Kaepernick, Blaine Gabbert, who finished last season as the team's starter, and Dylan Thompson.

The 28-year-old Lewis, who spent the 2015 season with the Philadelphia Eagles, reunites with Chip Kelly, his head coach in Philadelphia, who is now the 49ers' head coach.

Lewis did not play last season behind starter Sam Bradford and backup Mark Sanchez, who started two games.

Lewis joined the Eagles just before the regular season, after the team released Tim Tebow. The Eagles were Lewis' fifth NFL team.

ESPN Eagles reporter Phil Sheridan contributed to this report.