Backups Manuel, Cook in ‘open competition’

Offensive coordinator Greg Olson classified the battle for the Raiders’ backup quarterback job as “truly an open competition” between EJ Manuel and Connor Cook.

Manuel was the backup last season and appeared in two games while Derek Carr was sidelined by a fractured back, completing 24 of 43 passes for 265 yards. He holds the edge in experience, having previously played in 28 games with 17 starts over four seasons with Buffalo.

Cook, the Raiders’ fourthround pick in 2016, has appeared in two NFL games, both as a rookie, when he replaced injured backup Matt McGloin in Week 17 and started the AFC wild-card game. He has taken the majority of second-team reps this offseason.

Those reps have been erratic, which Olson indicated Saturday when asked what Cook must do to become a reliable quarterback.

“He’s got to be much more consistent,” Olson said Saturday. “We’ve seen some good things from him. But he’s got to do a much better job of taking care of the football and more consistent play.”

Olson did say that both Manuel and Cook, along with starter Carr, have taken well to the “hard coaching” of head coach Jon Gruden, who is notoriously demanding of his quarterbacks.

“I think they’re developing a bit of a thick skin,” Olson said. “They know that everything that he tells them is meant to improve them. … I think they appreciate the hard coaching, and they have responded.” Real deal: The Raiders will hold their first padded practice Sunday, which Olson said will give a better idea of how the offense has picked up the running scheme of new line coach Tom Cable.

“We’ve been through three days and had very minimal mental errors,” Olson said. “We’ll find out more once we get into some of the live work, (but) we’ve been pleased with where they’re at mentally.”

Cable has a reputation for favoring zone-blocking schemes, but has said he would like to have a “good mix” of zone and power runs in Oakland. Running back Doug Martin said he sees the offense as capable of doing “a little bit of everything.”

“Getting the pads on, we’ll definitely get a real feel of the timing as well as … just the run-blocking schemes,” Martin said. “It’s going to be good work for us.”

Roster move: The Raiders signed offensive lineman Oday Aboushi, who started eight games under Cable last season in Seattle and previously played for the Jets (2014) and Texans (2015-16).

Aboushi (6-foot-5, 315 pounds) takes one of two open 90-man roster spots created when the Raiders placed Khalil Mack and Vadal Alexander on the reserve/did not report list Friday.