Any time the Green Bay Packers have allowed one of their free agents leave, they've felt they had someone waiting in the wings to take his place.

They let Cullen Jenkins go because they had Mike Neal.

They let Greg Jennings go because they had Randall Cobb.

They let James Jones go because they have Jarrett Boykin.

The times they haven't had a replacement, they've panicked and paid premium contracts. Ryan Grant, A.J. Hawk and Brad Jones can all attest to that.

So when the Packers let center Evan Dietrich-Smith go to Tampa Bay for a deal they could have easily afforded (four years, $14.25 million), it spoke volumes about their confidence in 2013 fourth-round pick JC Tretter. They want him to be their starting center in 2014.

This week, they hosted Indianapolis free agent interior lineman Mike McGlynn on an official visit, which is a sign they're not standing pat after losing Dietrich-Smith. McGlynn is a low-level free agent even though he has started 48 games for three teams and would appear to be a veteran option were he signed.

At the NFL owners meetings, coach Mike McCarthy wouldn't commit to Tretter as his starter, but he admitted that if Tretter hadn't suffered torn ankle ligaments doing a fumble drill in organized team activities in June, he would have given Dietrich-Smith a run for the starting job.

"Good question," McCarthy said when asked if Tretter might have been the starter last season if he had stayed healthy. "We obviously were very excited about him when we drafted him."

The thing the Packers really like about Tretter is that he's as athletic as Dietrich-Smith yet stands 1¼ inches taller, weighs about the same and tested slightly better in combine drills coming out of college. He would be quarterback Aaron Rodgers' fourth center in four years, but there doesn't seem to be any concern about the Ivy Leaguer's ability to handle the mental challenges of the job.