Russell got in some reps in drills with first-team receivers, but for the most part played with the third team offense as he learns a new system.
He'll work his way up the ladder, with coach Lane Kiffin determining when he gets to take the next rung.
"I just want to go in and be prepared to compete for the job first off," Russell said. "Whether it's right now or I sit behind a guy and push him through practice, or however long it takes, I'm just ready to go in and compete."
The best guess is it won't take McCown long to demonstrate he is a better fit for the Kiffin offense than Walter and assume the No. 1 job.
Then it's a matter of whether Russell is capable of being the backup should McCown get hurt, or if Walter is the safer bet.
Kiffin is uninterested in working it all out in early May, not with training camp and four preseason games to go.
"It's not going to be a plan of, 'He's not starting this year,' or 'he's starting the eighth game,' or, 'he's playing the fourth quarter, or two series,'" Kiffin said. "He's going to play when he's ready to play. That might be Day 1. It might be Year 3.
"There's a lot of variables that go into that. Matt Leinart had never thrown a pass in college and won a national championship his first year starting. There's all different kinds of scenarios."
The Raiders coach resisted the suggestion of working Russell in with a smaller package of plays or changing the existing playbook to fit the player.
"We won't integrate anything into our offense to get someone on the field faster," Kiffin said. We have a system that we're going to run and we're extremely excited about how he fits into that system."
Russell often played in a spread formation at Louisiana State, and Kiffin said the Raiders already had shotgun plays in the playbook.
"He's got a gun," wide receiver Ronald Curry said. "Aaron Brooks, too. Aaron Brooks threw hard. Kerry Collins threw hard, too. He throws just as hard, but he's got great touch with the ball. He's going to be pretty good."
Defensive tackle Warren Sapp liked what he saw on Day 1, but stressed that it was still only May.
"He's a monster of a man, I'll give him that," Sapp said. "But this game has a great way of humbling you. The kid, he's working and he has a good attitude. He ain't shy, that's what I like about him. He's not shy. And he throws a good ball."