The Cardinals need to upgrade the roster after a poor 2018 season, and while the No. 1 overall pick awaits in April, first comes free agency. General Manager Steve Keim has significant cap space to use for the first time in his tenure and could be aggressive. We will take a look at each position group in the days leading up to free agency, which begins on March 13.

Free agent primer: Offensive Line

More free agent analysis: WR I LB

Cap hit of players under contract for 2019 (via OverTheCap.com): T D.J. Humphries ($9.63 million); G Justin Pugh ($7.3 million); C A.Q. Shipley ($1.18 million); C Mason Cole ($795,879); G Rees Odhiambo ($720,000); T Will Holden ($645,000); T Korey Cunningham ($587,268); G Colby Gossett ($570,000); T Zack Golditch ($570,000); G Coleman Shelton ($495,000); T Justin Evans ($495,000); G Will House ($495,000).

Scheduled free agents: T Joe Barksdale; G Mike Iupati; G Oday Aboushi; G/T John Wetzel (restricted); G Jeremy Vujnovich (exclusive rights); C Daniel Munyer (exclusive rights).

Need: High

Analysis: The Cardinals had trouble all across the offensive line in 2018, as injuries and ineffectiveness contributed to a meager offense. None of the projected starters in training camp finished the season on the active roster, and even when the group was healthy, it was subpar, which will lead to a search for upgrades.

Humphries is expected to remain the starting left tackle. He is solid when healthy but has missed 21 of 48 games the past three years. Pugh should slot in at one of the guard spots. He didn't live up to expectations after signing a lucrative deal in free agency last year and will look to bounce back. Cole started every game at center after Shipley missed the season with a torn ACL. They are both under contract and expected to compete for the starting job.

The Cardinals' big holes are at right tackle and one of the guard spots. Barksdale was signed late in the season and filled in capably. He would like to return, and the Cardinals must decide if there is a better option on the open market. Aboushi played well down the stretch after joining the team in late October, while Wetzel has been a versatile backup the past few years. They could be useful pieces if re-signed.

 Keim has been willing to spend money on the line in past years – Pugh, Iupati and tackle Jared Veldheer were all given big contracts – and that pattern could continue this offseason if the right players are available at the right price.

Notable past free agent offensive line signings: Pugh (2018); Andre Smith (2018); Alex Boone (2017); Earl Watford (2017); Evan Mathis (2016); Iupati (2015); Shipley (2015); Veldheer (2014); Ted Larsen (2014); Eric Winston (2013); Adam Snyder (2012); Daryn Colledge (2011); Rex Hadnot (2010); Mike Gandy (2007); Al Johnson (2007); Milford Brown (2006); Oliver Ross (2005); Pete Kendall (2001); Mike Gruttadauria (2000); Lester Holmes (1998); Lomas Brown (1996).