After reporting to camp, Ivey failed his conditioning run a week ago. He had been working out and watching practices until being cut.
Raiders coach Dennis Allen said there's a chance Ivey could be resigned if he gets into better shape.
"We'll keep all options open and do anything we can to try to help this football team, but right now it wasn't something that we felt like was going to help the team," Allen said.
Ivey, who played one game for the Browns in 2010 and spent part of last season on the Raiders' practice squad, was listed at 341 pounds and was the heaviest player on the team. No other Raiders DT has that classic NT bulk. But Allen said he's not about to scrap his plans to incorporate a 3-4 scheme into his defense.
"It won't change it at all," Allen said. "Dallas has played 34 defense with an undersized nose for a lot of years now so I don't really worry about that. If we decide to put some 3-4 groupings out there, we just gotta change up how we use them."
Jones hurts hamstring: Second-year RB Taiwan Jones, who missed the final six games last season with a hamstring injury, left practice early Sunday after feeling pain in his hamstring.
"I just got a little knot in my leg," Jones said. "Just being a little extra cautious since last year. Just being a little cautious. ... I've got my mind set that I'll practice tomorrow. We'll see how it goes."
More hamstring woes: WR Denarius Moore, who has battled a hamstring injury since minicamp in June, missed practice.
"It's a conern, you know, because it's been a nagging type of deal," Allen said. "So we got to make sure that we're diligent in the rehab process and make sure we continue to get that strengthened so that it's not an issue during the season and we're not dealing with this on an everyday or every week basis."
Janikowski in midseason form: With around 1,000 fans looking on, Sebastian Janikowski boomed a 61-yard field goal during practice.
"I was working on it yesterday on the other field," Janikowski said. "I hit a 70-yarder, so I figured why not? I hit it great. ... The wind was kind of helping it a little bit."
Janikowski kicked a 63-yarder last season against Denver, tying the NFL record.
Earlier in practice, Janikowski split the uprights and landed the ball on a film crew platform, high above the field.
"I heard some guy yelling in the stands, 'A hundred dollars if you hit that guy,'" he said. "I was aiming at him. It was fun. It was just for fun."
Extra points: DT Richard Seymour (knee) left practice early. "More preventative than anything else, but it's dealing with his knee," Allen said. ... TE Richard Gordon (hip, lower leg infection) returned to practice. ... LB Aaron Curry (knee), P Shane Lechler (knee) and WR Eddie McGee (hamstring) missed practice.
Follow Raiders reporter Eric Gilmore on Twitter: @CBSSportsNFLOAK.