Dec 6, 2014; Boise, ID, USA; Fresno State Bulldogs wide receiver Josh Harper (3) runs for a first down in the first half at Albertsons Stadium against the Boise State Broncos. Boise State defeats Fresno State 28-14. Mandatory Credit: Brian Losness-USA TODAY Sports

The Oakland Raiders found early success in the 2015 NFL draft with Alabama standout Amari Cooper and dual-threat tight end Clive Walford, but they continued to beef up their roster after the final round. Oakland has added 18 Undrafted Free Agents this offseason.

Although expectations for an UDFA aren’t high, the Silver and Black have been able to find recent success with some Undrafted Free Agents currently on the roster.

Rod Streater, an Undrafted Free Agent out of Temple University, has registered 108 receptions for 1,566 yards and eight touchdowns in 35 games with Oakland, as he is entering his fourth season in the NFL.

The Raiders’ leading receiver in yards in 2014, Andre Holmes, also entered the league as an Undrafted Free Agent out of Hillsdale College. Holmes brought in 47 receptions for 693 yards and four touchdowns.

Raiders starters Marcel Reece and Marquette King have also managed to produce at a high level in the NFL after entering the league as Undrafted Free Agents.

Here are Oakland’s top five UDFA’s looking to make an impact in 2015.