The move was somewhat of a surprise given the timing, coming one day before the Bills face the Los Angeles Chargers in their home opener.
Also, Buffalo has a paucity of offensive weapons and is coming off a dreadful Week 1 performance, managing only 153 total yards in a 47-3 drubbing by the Baltimore Ravens.
Kerley had two receptions for seven yards in the season opener. Zay Jones was the Bills' leading receiver in the season opener with three catches for 26 yards.
A fifth-round draft pick of the New York Jets in 2011, Kerley recorded 22 receptions for 217 yards and a touchdown in eight contests for the Jets in 2017. His season was interrupted by a four-game suspension due to a suspension for performance-enhancing drugs.
Kerley had a strong season with the San Francisco 49ers in 2016, hauling in a career-high 64 catches for 667 yards and three touchdowns.
Jones and Kelvin Benjamin are expected to be the starters for Sunday's game against the Chargers, which will mark the first career start of Bills rookie quarterback Josh Allen.
In a corresponding roster move Saturday, Buffalo signed defensive tackle Robert Thomas from its practice squad. The 6-foot-1, 331-pound Thomas appeared in 15 games in a reserve role with the New York Giants last season, collecting 16 tackles.