The first wave of free agency has passed without the Lions adding or officially subtracting a cornerback (discussions are ongoing with free agent Rashean Mathis). The combine and several pro days have also passed without much chatter about the top draft-eligible cornerbacks.

The Lions have spent the bulk of their time, seemingly, on pass rushers, pass catchers and safeties.

Is it possible, after signing Chris Houston to five-year, $25 million contract before last season, and drafting Darius Slay (second round, 2013), Bill Bentley (third round, 2012), Chris Greenwood (fifth round, 2012) and Jonte Green (sixth round, 2012), the Lions feel set at the cornerback position?

Not likely.

“We have a game in September,” general manager Martin Mayhew said during the league meetings last week. “The plan is to get the best two or three cornerbacks we can get by then, however we can get them: free agency, draft, whatever.

“There is no plan anywhere on our roster where we’re just going to stand pat. We are always trying to improve.”

But Mayhew and coach Jim Caldwell may want to use the offseason program to assess the cornerbacks on the roster before extending any more resources to the position.

“There is a new coaching staff, as you know, and so everybody has an opportunity to impress the new coaching staff,” Mayhew said.

Although Mayhew remains high on the current crop of corners, Houston and Slay in particular, there are serious question marks.

Houston will turn 30 in October and is coming off his worst season in Detroit. Mayhew, though, said during the combine this year the 2013 season was an aberration.

“I’m very confident in Chris,” Mayhew said. “He’s a veteran player and he knows how to play the game. He had some injury issues and he had some off-field issues last season. We’re still confident in Chris’ game.”

Slay endured an up-and-down rookie season in which he missed three games with injuries and started only four of the 13 he played. Bentley, though he has adapted well to the nickel corner position, has battled injuries the past two seasons.