Mailbag: Can we see an A.J. Jenkins repeat?

Weekend mail call:

Isaac from Salinas, Calif., wants to know if I think the 49ers could try to replace Jim Harbaugh with Jon Gruden or Bill Cowher in 2015.

Bill Williamson: I really doubt it. If the Harbaugh situation blows up after this season, I would think the 49ers would first look at an existing assistant such as offensive coordinator Greg Roman, defensive coordinator Vic Fangio or defensive line coach Jim Tomsula. I wouldn’t think a big-name, out-of-work coach is where the 49ers would first look if somehow Harbaugh is not in the picture.

James from New York wants to know what I think the difference between A.J. Jenkins and Brandin Cooks.

BW: It’s an interesting question and I don’t know if there is a simple question. Cooks is smaller and faster than Jenkins, who the 49ers took with the No. 30 pick in 2012 and they ended up trading him to Kansas City last summer. I understand the question. But I don’t know if it’s a comparison. What I think you want to know is how can we be sure Cooks, who the 49ers could target with the No. 30 pick in the draft, isn’t another highly rated college receiver who can’t translate his game to the NFL. There is no answer to that yet. We have to see what he can do. Receiver is often a boon-or-bust position. So it is up to the 49ers to make a decision on if they feel they can make Cooks a productive NFL player or not.

Kenneth from Visalia, Calif., wants to know if I think the 49ers could sign Terrell Owens or Chad Johnson.

BW: I know the 49ers have brought in aging stars before. But the ship has sailed on these guys. It’s over, folks.