Cockrell, of course, was the cornerback signed on final cutdown day after he had been cut by the Buffalo Bills in the firsts cuts the previous week.
The 6-0, 190-pounder was drafted in the fourth round in 2014 by the Bills and played in seven games last season, but took part in only 11 defensive snaps. Nonetheless, Cockrell said he's ready for whatever may come his way Sunday.
"I feel pretty comfortable," he said. "The coach has been taking extra time with me, which has really helped me progress fast. And the players, I can't say enough about the players. They embraced me as a teammate and that helps a lot."
Cockrell has only been with the team for 11 days but he's apparently a quick study. After all, he graduated from Duke with a degree in political science and is the son of a former Columbia University football player. Cockrell also ran the 40 in 4.44 and had a vertical jump of 39 inches at his pro day, so he's smart, tall, fast and says the right things to reporters
"I'm going to communicate," he said as he touched on the day's primary coaching point. "That's what we need in the back end. I'm going to try to open my mouth and make sure that we have the right calls in and do my best to help this team win."
If Boykin can't recover from his groin injury, Cockrell will likely play a major role Sunday against San Francisco.
"They brought me in here to try to help the team win, and that's what I'm doing," he said.
COMMUNICATE OR DIE
The coaching staff sent the message loud and clear that the defense must communicate better, and it showed as the entire group was buzzing like bees on the practice field Wednesday.
"Yeah, we need to communicate better," said James Harrison. "That was obvious in our last game, and even into the preseason. Our focus now is doing a lot more communication, guys echoing the calls, so on and so forth."
Harrison was asked if the problems in the opener were the result of the first-teamers playing so little in the preseason.
"It's a combination of everything," he said. "That's from the top to the bottom. That's from the players to the coaches and so on. You can't just point your fingers at one thing, like playing together enough, or that we didn't do this or that. It's a combination of everything. We didn't get calls in time, and when we did get the calls in we're not communicating. It's a combination of everything."
Does he expect improvement on Sunday?
"Of course. Of course," he said. "We expect to get better each week."
BE PHYSICAL OR LOSE
The 49ers rushed for a league-high 230 yards at a league-high 5.9 yards per carry on the strength of a new zone-blocking scheme up front and a new running back, 235-pound second-year man Carlos Hyde, in the backfield.
With Steve McLendon working at his nose tackle position as well as at defensive end next to Daniel McCullers at times on the second team, it's obvious the Steelers are expecting a physical game. And that's fine with the rest of the linemen.
"I love a game like that," said Stephon Tuitt. "It's just downhill running and the best man wins. It'll be physical and we'll come out of this game sore, but we're looking forward to being the best man."
Tuitt in particular looked like a man possessed at Wednesday's practice as he broke up runs in the backfield with gusto.
"Just getting better," he said. "I get better every week. I'm getting my ankle back stronger. It's still a high ankle sprain, so you want to make sure you take care of it, but like I said, getting stronger every week."
Tuitt was asked to describe what the 49ers offense looked like in beating the Minnesota Vikings, 20-3, on Monday night.
"They're definitely coming out there to try to run you out the stadium, and that's one thing we can't let them do, run us out of our own stadium," he said. "We've got to make sure we come out there ready to play them on the defensive side of the ball and play them pound for pound. We're physical. We're the Pittsburgh Steelers. So we've got to make sure they know that."