Much of our debate on Green Bay's pre-draft needs has centered on offensive tackle and outside linebacker. But some of you suggested an alternate focus during last week's discussion: cornerback.

A cornerback with sophisticated coverage skills is one of the four most-difficult targets in any draft, a list that (in my opinion) also includes pass-protecting left tackles, pass-rushing defensive ends and competent quarterbacks. That's one of the reasons you saw the Packers issue a high tender to restricted free agent Tramon Williams, who has made 20 NFL starts.

Another big reason is something we haven't discussed much in this space: The uncertain future of longtime starter Al Harris, who at 35 is rehabilitating a left knee injury that was more serious than we originally thought.

Harris has been chronicling his recovery over at the National Football Post, but coach Mike McCarthy spoke with realism last month when discussing Harris' timetable for returning to the field. McCarthy called it a "real serious injury" and indicated that team doctor Patrick McKenzie performed two separate procedures on him to regain full range of motion.

"We'll just continue to watch that and see how he responds," McCarthy said, adding that it's "probably fair" to compare Harris' timetable to the one right tackle Mark Tauscher followed last year. Tauscher wasn't ready to start practicing until October.

If Harris isn't ready to start the season, Williams would start opposite Charles Woodson. In that scenario, the Packers would be counting on several other players to recover from injuries, including Will Blackmon and Pat Lee, to provide depth.

A first-round cornerback might not be a dramatic need, but it wouldn't be a luxury either. For what it's worth, here are Mel Kiper's top five available cornerbacks:

1. Florida's Joe Haden

2. Alabama's Kareem Jackson

3. Rutgers' Devin McCourty

4. Boise State's Kyle Wilson

5. Florida State's Patrick Robinson