[Editor’s note: This preview was originally published on Feb. 27, 2017, and updated on March 6 to reflect changes in the market do to franchise tags, re-signings, cuts, etc.]

What you need to know

The 49ers were unquestionably one of the worst teams in the NFL last season. With holes at virtually every position, the 49ers should be open to upgrading wherever possible, and they’ll have plenty of money to explore options through free agency.

Salary cap room

$93,480,264 (second in NFL; as of 3/6/17)

Biggest needs

Wide receiver

Defensive interior

Edge

Guard

Notable free agents

Blaine Gabbert, QB, 39.0 overall grade in 2016

Gerald Hodges, ILB, 82.4

Glenn Dorsey, DI, 38.0

Must re-sign

Gerald Hodges, ILB, 82.4 overall grade in 2016

Hodges is just 26 years old and finished 2016 with the 21st-highest overall grade among qualified linebackers. Hodges’ 15 run stops last season were the 15th most out of 58 linebackers, and he and NaVorro Bowman teamed up to create one of the few formidable units that the 49ers possessed in 2016.

Dream splash

Calais Campbell, DI, Arizona Cardinals, 90.4 overall grade in 2016

A dream offseason would see the 49ers upgrading significantly at multiple positions, as their roster is just barren of game-changing talent, so it’d make sense that Campbell, the No. 1 player on our free agent big board, would be a major grab. Campbell may be over 30 years old, but he’s currently playing the best football of his career, and teaming him up with DeForest Buckner and Arik Armstead would give San Francisco a trifecta of versatile defensive linemen that could anchor the entire unit.

Top 2017 free agency prospects

Alshon Jeffery, WR, Chicago Bears, 77.6

Even coming off a down, injury-riddled season, at 27 years old Jeffery has already proven that he can be a dominant NFL receiver. Jeffery finished fourth among all wide receivers in 2015 in yards per route run at 2.87, and similar to Anquan Boldin in his heyday, Jeffery has demonstrated the ability to routinely beat defenders at the catch-point, which would bode well for a QB like Colin Kaepernick who has never been particularly accurate.

Brandon Williams, DI, Baltimore Ravens, 75.9

Any fantasy football player from last season can tell you that starting a running back against the 49ers was a consistent recipe for success, the 49ers were routinely gashed on the ground by opposing offenses. Williams, despite coming off a bit of a down year, has been one of the premier run-stuffing defensive tackles since he stepped onto an NFL field. Williams’ 99 stops over the past three seasons rank as the ninth-most among all interior defenders.

Kevin Zeitler, G, Cincinnati Bengals, 87.1

Out of 73 qualified offensive guards last season, Joshua Garnett and Zane Beadles ranked 70th and 72nd, respectively, in terms of overall grade, with both struggling mightily in both pass-protection and as run blockers. Zeitler finished ninth among guards this season with a run-blocking grade of 83.1 and allowed just 19 total pressures, compared to the 38 surrendered by Garnett and the 36 allowed by Beadles.