And then there was one.

The Raiders confirmed the signing of offensive lineman Tony Bergstrom, their third-round pick out of Utah, leaving only wide receiver Juron Criner, a fifth-rounder from Arizona, unsigned.

Bergstrom signed his contract late Friday night at team headquarters in Alameda and will report to training camp Saturday in Napa. He spent most of his college career at tackle, but he'll begin his Raiders career as a backup guard, behind starters Cooper Carlisle and Mike Brisiel.

Brisiel, a free agent pickup from Houston, is locked in at right guard, but Bergstrom could put some heat on Carlisle during camp or at some point during the season. Carlisle is entering his 13th NFL season.

The 6-foot-5, 310-pound Bergstrom was the 95th overall pick and the Raiders' first selection in April's draft. He earned first-team All-Pac-12 honors as a senior last season.

The Raiders are scheduled to begin reporting to camp in Napa on Saturday afternoon. They'll undergo physicals and attend administrative meetings on Sunday then have their first practice Monday morning.

Criner is one of four unsigned draft picks in the NFL. The other three are first-rounders. He'll all but certainly sign his contract in time to take part in Monday's practice.

Criner caught 209 passes for 2,859 yards and 32 touchdowns during his college career at Arizona. He turned in a series of impressive performances during the offseason at OTAs and minicamp. His emergence is likely one reason why the Raiders traded veteran wide receiver Louis Murphy to Carolina.

Follow Raiders reporter Eric Gilmore on Twitter: @CBSSportsNFLOAK.