Todd McShay mock 4.0: 49ers select CB Trae Waynes

Free-agency defections and a pair of sudden retirements have changed the tenor of the San Francisco 49ers' offseason, as well as the thinking behind a mock draft or two.

Count ESPN NFL draft Insider Todd McShay among the converts.

McShay has selected Michigan State cornerback Trae Waynes, the top-rated corner in this class by many observers, for the Niners in his Insider Mock Draft 4.0Insider, released Monday. This after McShay selected receivers in his first two mocks for the 49ers in Michigan's Devin Funchess and Ohio State's Devin Smith and defensive lineman Arik Armstead in his third mock.

The selection of Waynes is more than intriguing, especially with all three of those afore-mentioned picks still on McShay's board when the Niners' spot came up at No. 15.

It also makes sense in that the Niners have lost both starting cornerbacks, Perrish Cox signing a reported three-year, $15 million deal with the Tennessee Titans and Chris Culliver heading to Washington on a four-year deal worth up to $32 million.

Sure, the Niners landed Shareece Wright in free agency, signing the former San Diego Chargers corner who has started his last 27 games. But he has also led the NFL in pass interference penalties since 2013.

Plus, the Niners did use four picks on DBs in last year's draft, including first-rounder Jimmie Ward, who was use mostly as a nickelback before a foot injury ended his season, and Tramaine Brock, who started the season opener, returns after an injury-plagued 2014 season.

The 6-feet, 186-pound Waynes, though, blazed to a 4.31-second 40-yard dash at the NFL combine and his skill set is best utilized in press-man or Cover-2 schemes. He had three interceptions and eight pass breakups for the Spartans as a junior last season.

He was asked at Michigan State's recent pro day if he thought he could start as a rookie in the NFL.

"If I have to jump right in there, I'm going to take advantage of it and learn as quickly as I possibly can and hopefully pick up on the system quickly with the help of other players and coaches," Waynes said. "If I get to sit back and learn from people, great. That's something I did here [at Michigan State] and it clearly benefited me in the best way possible.

"I'm going to try to get on the field as quickly as I can and make an impact."

Might that be with the 49ers, though?