Cook, a second-year man out of South Carolina, appeared in 12 games for the Jets over the last two seasons, and recorded six special teams tackles in that time.
"Emaunel Cook will be an addition right away for special teams," Harbaugh said. "Of course, we feel he has a future as a safety, too, but that goes hand-in-hand with being a football player. But he's a guy that can help us potentially immediately as a special teams guy. We'll have to see how quickly we can get him up to speed. Whether it's this Sunday or not, I don't know."
There was a report out of New York that Cook was released by the Jets on Monday after he was late to a conditioning workout.
Cook disputed that report today.
"I really don't know, I wasn't late," Cook said. "I don't know why.
"I met with (Jets general manager) Mike Tannenbaum. He said we need to make a move. He said he had a better player. They made a push for somebody else."
Meanwhile, wide receiver Lee Evans certainly would have preferred not to have missed seven games this season because of a lingering ankle injury, but all the missed time might end up having a major benefit.
As the Ravens approach the final stretch in the regular season, Evans has had minimal wear and tear on his body, and is probably in much better shape health-wise than most players who have played a full 11 games to this point.
"You don't see that too often, people with fresh legs in December," Evans said. "I'm feeling good and looking forward to it."
Evans made his first catch since Week 2 during the 49ers game, and says it was nice to get back on the score sheet and help his offense in a key game.
"Obviously it felt good to get the win but also to get involved and make some plays," Evans said. "It was a good start and a good way to contribute. But there's still a lot more plays to be made and a lot more work to be done. The hard road still lies ahead."
In the end, the veteran wide receiver admits that it could be somewhat of a blessing in disguise that he missed all that time. He stayed positive through the ankle injury and now is in a position to contribute down the stretch.
"It could be," Evans said. "It's all about what you make of it. I'm certainly excited to be in this position."