RENTON, Wash. --The Seattle Seahawks' coaching staff has emphasized ball security with rookie running back Alex Collins throughout training camp. And they had been thrilled with the results. Every day at practice, defenders would try to rip the ball out of Collins' hands, but he never gave it up.

During Sunday's scrimmage, however, Collins fumbled on an early drive, resulting in a turnover for the offense -- or at least that's how the officials ruled it.

Alex Collins has been working on securing the ball during training camp. AP Photo/Ted S. Warren

"The defense just made a big deal about it, picking it up," Collins said afterward. "Trying to move on to the next play, and they're running down the field."

So it wasn't a fumble?

"No, no," Collins said. "They'll see it on film."

Pete Carroll seemed to back him up.

"I didn't see that fumble, how it happened," Carroll said. "The play looked like it was over."

That one play aside, Collins did well with a heavy workload. Thomas Rawls (ankle), C.J. Prosise (hamstring), Christine Michael (illness) and Zac Brooks (hamstring) all sat out the mock game. Collins scored a red-zone touchdown on the ground, but he was more impressive as a receiver. On one play where quarterback Trevone Boykin scrambled away from pressure and rolled to his left, Collins adjusted from his initial flat route and turned upfield. Boykin connected with him for what looked like a 50-yard score.

Asked if the receiving responsibilities in the Seahawks' offense are different than what he had to do at Arkansas, Collins said, "In college, it was more you-leak-out-last-minute kind of deal. But we weren't primary threats as far as the first read. But here, I can be the first read on any given play, and I can be the hot guy, they're-throwing-it-to-me-now kind of deal. So it's definitely different. They stress it a little bit more here."

Collins will be a player to keep an eye on when the Seahawks open the preseason on Saturday.

Other notes from the scrimmage: