GREEN BAY, Wis. -- If there’s a position that offers the Green Bay Packers a greater unknown than running back, then it hasn’t been identified yet.

With the offseason suddenly upon the Packers, one of their priorities is to sort out that spot.

Eddie Lacy says he wants to come back, but at what price?

Ty Montgomery looks like a full-time running back, but can he handle more than a dozen carries per game -- something he did only once this past season after he converted from receiver?

And who knows what’s in the future for James Starks, who hasn’t played since he suffered a concussion in a Dec. 12 car crash, or in-season pickup Christine Michael.

It’s why Lacy, whose rookie contract is set to expire, will be one of the Packers’ most important decisions in free agency.

As always, financials will play a critical part in every decision. The Packers have more than $7.9 million in unused salary-cap space from 2016 that they’ll be able to carry over into this year, according to the NFL Players Association.

Here’s a look at the Packers’ free agents to-be on offense (with the expiring contracts of defensive and special-teams players coming later):

Lacy: It looked as if it would be a bounce-back season after his disappointing year in 2015. He averaged 5.1 yards per carry before his season came to an end after just five games because of an ankle injury. He underwent surgery and has only recently been able to ditch the walking boot and scooter. Lacy’s weight will always be an issue. After trimming down last offseason, he appeared to regain at least some of the weight he lost while working out with P90X founder Tony Horton, though he was still effective. When last seen around the facility, he looked at least as big as he was at this time last year, when coach Mike McCarthy called him out publicly for being overweight. Perhaps the Packers and Lacy would agree on a short-term deal similar to the two-year, $6 million contract Starks signed last offseason. 2016 pay: $867,602 base salary, no bonuses

Michael: Other than the 42-yard touchdown run against the Bears in Week 15, Michael was little more than a change-of-pace back who spelled Montgomery at times. The Packers inherited the remainder of his $675,000 minimum salary when they claimed him off waivers in November. 2016 pay: $277,941 in prorated portion of base salary

Jared Cook, TE: Quarterback Aaron Rodgers said the veteran who played under a one-year, $2.75 million deal this season “needs to be near the top of the priority list, the way he played this year.” Cook called this season the most fun he’s ever had in his eight-year NFL career. Although Cook had a couple of drops in the NFC title game loss to the Falcons, he made a major impact after he returned Nov. 20 from an ankle injury that cost him six games. Including the playoffs, Cook averaged 12.6 yards per catch and had three touchdowns in 13 games. 2016 pay: $2.6 million in salary and bonuses (missed out on $150,000 in weekly roster bonuses during ankle injury)

T.J. Lang, G: With Lang having made his first Pro Bowl, there should be plenty of demand for him on the open market. The only thing working against him is age; he’ll be 30 in September. But Lang has shown the ability to play through multiple injuries -- and play effectively. Could it work against him that the Packers let go of fellow guard Josh Sitton before last season and barely missed him, if at all, after Lane Taylor stepped in at a lower price? The Packers answered one of their offensive line question before the season, when they gave left tackle David Bakhtiari an extension that averages $12 million a year. 2016 pay: $5,043,750 in base salary and bonuses (missed out on $56,250 in weekly roster bonuses by missing three games with a foot injury)

JC Tretter, C: A starter for the first seven weeks, Tretter lost his job when he suffered a knee injury. He had regained the job because Corey Linsley, who replaced an injured Tretter in the 2014 preseason, wasn’t ready for the start of the year because of a hamstring injury. Linsley conveniently came back just as Tretter got hurt again. After unsuccessfully trying to return late in the year, Tretter underwent knee surgery last week but said the recovery time wasn’t expected to be long. 2016 pay: $675,000 base salary, no bonuses

Don Barclay, G: He started one of the three games Lang missed with a broken foot (Nov. 20 against Washington) but was pulled after a pregame shoulder injury rendered him ineffective. The Packers love rookie Lucas Patrick, who spent the season on the practice squad and could replace Barclay as a backup guard next season. 2016 pay: $700,000 in salary and bonuses