Vikings have cap space to make a mark in free agency, but will they?

The first cards of the NFL's annual high-stakes poker game will be dealt Saturday, when teams will be allowed to open negotiations with free agents from other teams.

Vikings General Manager Rick Spielman says he plans to sit back at the poker table in the early going while desperate teams are tossing the biggest bets out onto the felt. But one can't help but notice the stack of chips that he has piled up at his end of the table.

With last week's release of starting guard Charlie Johnson and Wednesday's trade agreement to send backup quarterback Matt Cassel to the Buffalo Bills, the Vikings will enter free agency with about $25 million in salary cap space to use to fill several needs. Well, assuming Spielman doesn't have another move or two left up his sleeve.

The Vikings could top $30 million in cap space if they release outside linebacker Chad Greenway or convince him to take a pay cut. Spielman has said he would like Greenway to finish his career with the Vikings. But if that was just lip service, one would hope he would cut ties with Greenway now so he has a chance at finding a favorable situation elsewhere.

Wide receiver Greg Jennings seems likely to be back in 2015, but the Vikings might want to lower his salary and cap hit to bring it more in line with his modest production.

And while nothing appears to be imminent on the Adrian Peterson front, something could always change with the disgruntled running back and his $12.75 million salary with the official start of free agency and the opening of the league's trade window looming Tuesday at 3 p.m.

Still, even if Spielman decides to stand pat for now, the Vikings will have the chips needed to make a splash, which he admitted they could do if "something unique" presents itself.

That said, Spielman and coach Mike Zimmer both have recently stated that it is their preference to build a contender through the draft and save the costly contracts for their own young and ascending players. After all, recent first-round picks such as Harrison Smith, Xavier Rhodes and Teddy Bridgewater will be up for new deals in the coming years.

And it's not as if the Vikings are a player or two away from hoisting the Lombardi Trophy.

Spielman said in January that the Vikings have targeted eight areas they needed to address in the offseason. While he didn't specify those needs, the best guess is that they are at cornerback, safety, defensive end, middle linebacker, wide receiver, guard, offensive tackle and running back, the latter depending on what happens with Peterson.

And you can add a veteran backup quarterback to the list now that Cassel is headed to Buffalo.

The Vikings, who have the 11th overall pick among their seven selections, will attack many of those areas in the NFL draft, which begins April 30. But taking care of a few of them now will give them more flexibility to draft prospects based on talent instead of positional need.

Zimmer has said that a lot of "mistakes" can be made when teams spend for players unfamiliar to them, and he has confidence in his staff's ability to coach up "lower-end" free agents.

The Vikings have the chips, though, to make some aggressive plays in the free-agent poker game.

Will they really stay patient at the table or are they simply keeping their cards close to the chest?

Matt Vensel • matt.vensel@startribune.com