Amari Cooper

Oakland Raiders wide receiver Amari Cooper runs a route during practice in Alameda, Calif., on June 2, 2015.

(AP Photo)

For the fourth player picked in the 2015 NFL Draft, wide receiver Amari Cooper kept a low profile during the Oakland Raiders' OTAs. One reason is because he's "quiet," as Oakland backup quarterback Christian Ponder described the former Alabama star.

Another reason is because, from all accounts, Cooper has been as advertised for the Raiders after setting Alabama single-season records with 124 receptions for 1,727 yards and 16 touchdown catches in 2014 and Crimson Tide career marks with 229 receptions for 3,463 yards and 31 TD catches. There's been no news to report on the rookie's struggles to adjust to the NFL or how the Raiders could have used their pick more wisely.

Oakland coach Jack Del Rio has said Cooper is going to be "a good player" and is "one of the most polished receivers to come out of college in years." But he wants fans and media to remember Cooper is a rookie.

"I think we all need to be pushed," Del Rio said during OTAs when asked how Cooper had reacted to facing Oakland's veteran defensive backs at practice. "We all need to be coached, coached hard, demanded from. He's no different in that regard."

Other accounts coming out of the Oakland workouts have been more effusive.

"He adds an explosiveness to the offense," Oakland wide receiver Rod Streater told the Raiders' official web site. "I feel like he is going to come in and make an impact right away. The more playmakers you have, the better you are going to be. He is really going to help us win."

"To be a top-10 pick as a receiver means that you're bringing a lot to the table," Ponder told espn.com about Cooper. "He is a guy that works hard. He is quiet, but you can tell that he is coming in to work hard and to learn a lot. He brings a lot to this football team."

**VIDEO** WR Amari Cooper with a nice grab #Raiders pic.twitter.com/xBT5Vox4nK — Fallon (@FallonSmithTV) June 2, 2015

Del Rio said he was "excited" about getting Cooper, rookie tight end Clive Walford and free agent wide receiver Michael Crabtee on the field at the same time. Cooper already has impressed his fellow rookie:

I Didn't realize how fast coop was until I tried to make a block for him!!!! Blazing🏃💨💨💨 — Clive Walford (@OGSlick_46) June 3, 2015

Eric Edholm of Yahoo Sports reported an unidentified rookie wide receiver on the Raiders said he was "in awe" of Cooper.

ESPN NFL Insider Adam Caplan reported an unidentified team source called Cooper the "real deal."

Early word on #Raiders WR Amari Cooper, per team source: "Real deal. Almost no mental errors. Runs great routes, consistent route runner." — Adam Caplan (@caplannfl) June 5, 2015

Oakland Raiders wide receiver Amari Cooper jumps for photographers during the NFLPA Rookie Premiere at Los Angeles Memorial Coliseum on May 30, 2015, in Los Angeles.

Bill Williamson, who covers AFC West for ESPN.com, thinks Cooper could become Oakland's first 1,000-yard receiver since Randy Moss in 2005 as a rookie. The Pro Football Talk panel debated how Cooper would do in the NFL compared to an Alabama predecessor, Julio Jones, who has been a Pro Bowl pick in two of his three full pro seasons.

Cooper has been catching most of his passes from Oakland's backup quarterbacks, Ponder, Matt McGloin and rookie Cody Fajardo, because the Raiders' regular QB, Derek Carr, has been limited by a finger problem. Carr has been cleared to throw at Oakland's three-day, mandatory minicamp, which starts on Tuesday.