It took much longer than expected, but wide receiver Juron Criner, a fifth-round draft choice from Arizona, finally signed his four-year contract Sunday.

Criner was one of only three unsigned draft picks in the NFL. The other two are first-round picks.

Criner reported to training camp in Napa and will be on the field Monday morning when the Raiders have their first practice.

“You never know what’s going to happen in those negotiations, but we felt pretty confident all along that he would be in here for training camp,” Raiders coach Dennis Allen said.

During OTAs and minicamp, Criner turned in a series of impressive performances, putting himself in position to compete for playing time as a rookie. The 6-foot-3, 221-pound Criner caught 209 passes for 2,859 yards and a school-record 32 touchdowns during his college career at Arizona.

“He’s a big, athletic receiver that has a big catching radius, and he went and made some plays for us in OTAs,” Allen said. “His ability to be a big target for the quarterback was a positive.”

The Raiders on Monday traded veteran wide receiver Louis Murphy to Carolina. According to Allen, the “emergence” of Criner and wide receiver Rod Streater, an undrafted rookie from Temple, made trading Murphy a viable “option.”

The Raiders on Sunday also signed a pair of undrafted rookies, linebacker Chad Kilgore (Northwest Missouri State) and wide receiver DeAundre Muhammad (Indiana).

Oakland’s roster now stands at 89, one under the limit. All 89 players have reported to camp, Allen said. Players underwent physicals and conditioning tests and attended a variety of team meetings Sunday.

Follow Raiders reporter Eric Gilmore on Twitter: @CBSSportsNFLOAK.