Wide receiver Kerley acquired from Lions

Two days after slot receiver and punt returner Bruce Ellington was sidelined with a hamstring injury, the 49ers traded guard Brandon Thomas for Detroit’s Jeremy Kerley, the NFL Network reported.

Kerley’s job description? Slot receiver and punt returner.

Kerley, 27, a fifth-round pick in 2011, joins Torrey Smith as the 49ers’ only wideout with more than 36 career catches. At 5-foot-9 and 188 pounds, he’s a shifty wideout who had career lows in catches (16) and yards (152) last year. He had career highs in catches (56) and yards (827) in 2012, and has 182 catches and 2,225 yards in his career. He signed a one-year deal with the Lions after spending his first five seasons with the Jets.

Kerley led the NFL in punt returns (48) and ranked second in punt-return yards in 2015. He ranks 13th among active players in punt returns (134) and 17th in yards (1,250).

The trade comes a day after Ellington had what head coach

Chip Kelly termed a “precautionary MRI” exam after he was injured on a 4-yard punt return in a 21-10 preseason loss to the Packers on Friday. Ellington walked gingerly off the field and appeared distraught, burying his head in his hands, on the sideline. Ellington was not observed at practice Sunday.

Thomas, a 2014 third-round pick, didn’t play a snap last year. He spent the 2014 season on injured reserve because of a torn ACL he sustained prior to the draft.

Pears released: The 49ers released offensive tackle Erik

Pears, 34, who started 16 games last year in his lone season with the 49ers. Pears had been viewed as a potential swing tackle, capable of filling in if starters Joe Staley or

Trent Brown were injured. It’s possible the 49ers would move guard Anthony Davis to tackle if a fill-in was needed. Davis, of course, spent his first five seasons in the NFL at tackle. He recently switched positions and started at right guard Friday.

The 49ers also released tight end Busta Anderson, a 2015 seventh-round pick. Anderson spent last year on injured reserve with an ankle injury.