Vikings coach Mike Zimmer will field a much different team next season with 16 free agents questionable to return, including running back Adrian Peterson, and the retirement of linebacker Chad Greenway on Tuesday. Zimmer said the team is going to have to fill needs through the draft and free agency.

He'll get a lot of evaluation help from General Manager Rick Spielman, assistant general manager George Paton and college scout Scott Studwell.

"We're planning on being aggressive in free agency," Zimmer said. "Hopefully we can fill some holes that we need and then attack some of the rest of them in the draft. Rick and George and Scott and all those guys have done a really good job of evaluating all of these players and now it's going to come down to seeing which ones we can get."

The Vikings have $35.7 million in available cap space and that includes their allocated money for singing new draft picks, according to Zimmer said that's an important starting point.

"We do have some money and that's a good thing," he said. "We're going to try to spend it wisely, but we're not afraid to go out and spend."

Zimmer also said that while Peterson is a free agent and testing the market, the coach still is open to his return.

"I think Adrian is still a good back, and I think it's important for him to go out and see what his value is and then we'll sit down and talk," Zimmer said. "If he wants to come back, we'd like to have him back."

One other player Zimmer emphasized the team will try to get back is wide receiver Adam Thielen, who had 69 receptions for 967 yards and five touchdowns last season. On Wednesday, the Vikings placed a second-round tender on Thielen — meaning if he gets an offer in free agency and they don't decide to match it, the Vikings would receive a second-round draft pick as compensation. The relatively high tender should discourage most teams and keep him with the club in 2017 while a long-term extension is negotiated.

"We're hoping we get [a lot] those guys back," he said about the 16 free agents. "Adam Thielen has been a solid contributor to us, so he'll be a guy that we really work on hard to try to get something done here."

Draft analysis

The NFL draft will be April 27-29 in Philadelphia. Most of the Vikings front office staff was in Indianapolis for the NFL scouting combine last week. Zimmer analyzed the draft by positions.

"It's a limited group of [offensive] tackles," he said. "There's some developmental guys. The other guys will get picked high. We're going to have to be smart with that. We always have to look for those big guys that can pass protect."

Zimmer said other positions are better stocked.

"This [draft has] a really good group of tight ends, good group of defensive backs, good group of running backs … those three positions, I think, are the strength of the draft," he said. "There's some good defensive linemen coming out. This could be a good draft and hopefully we hit on some of these guys."

One player at the combine who caught a lot of people's attention, including Zimmer, was former Gophers defensive back Jalen Myrick.

"[Myrick] ran a 4.28 [40-yard dash]," Zimmer said. "He was the second-fastest player in the combine at all positions and the fastest player for the defensive backs. Minnesota has had some really good players come through there, and they had three or four players at the combine this week."

Trying to fill needs

The Vikings traded their 2017 first-round pick in the deal with the Eagles for quarterback Sam Bradford, but they always have been able to add quality players in later rounds.

"A lot depends on free agency," Zimmer said. "Defensively we're always looking for guys that can cover and guys that can rush the quarterback, that will never change. Offensively we're going to continue to need more receivers, we're going to need some more offensive linemen, obviously, and I think we want to make sure that we don't get pigeonholed into taking [only those] positions. If a defensive lineman is there with our first pick and he's the best player there, then I think we should take him."

He said the lack of picks doesn't bother him.

"This being a deep draft, I think a lot of these guys will get pushed down," he said. "There's several corners in this draft, defensive backs, the best safety group that has been out there and the best corner group. They all ran good, they're big-size guys. A lot of these guys will get pushed down into the second and third rounds, and we'll have some opportunities there."

When it comes to in-house replacements, Zimmer said he and the other coaches need to improve at developing young players. He mentioned former Gophers wide receiver Isaac Fruechte as one practice squad member possibly ready to make the 53-man roster.

"[Fruechte] has done a nice job throughout the course of the year," Zimmer said. "I think there's an opportunity for him to come in and help."

Greenway memories

On Tuesday, Vikings coaches and front office members attended Greenway's retirement announcement. All had positive things to say about one of the all-time great Vikings defensive players.

Studwell, who scouted Greenway at Iowa when the Vikings made him a 2006 first-round pick, talked about how unlucky Greenway was in his first NFL season. He got injured on the opening kickoff of the preseason and missed the whole year.

"It was one of those moments where, 'Oh, what the hell happened?' " Studwell recalled. "He tore his ACL on the kickoff, and those things happen, and obviously he recovered from it and the rest is history."

Studwell talked about his scouting trip to see Greenway.

"After we went down to [Iowa] and watched him play and watched him practice and talked to all the sources at the school, you know he was the kind of guy we were looking for from an athletic standpoint, from a personality standpoint, from an off-the-field perspective," Studwell said. "He has been a great player for us.

"You could tell he could run, he was a very good athlete, a converted quarterback and safety, he had great range. He played the game the way it is supposed to be played. He was 110 percent every snap, and you just knew that every day he stepped on the practice field, he tried to get better. It carried over to here as well."

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