Fitzgerald showed his support of Wilks via a text to NFL Network's Ian Rapoport amid reports that the coach could be ushered out after his lone season with the Cardinals (3-11).
"We all would want him back," Fitzgerald wrote.
Rapoport added that team owner Michael Bidwill has made "no firm decision" regarding Wilks, who was hired in January.
ESPN's Adam Schefter reported Sunday morning that the Cardinals are not expected to retain Wilks at the end of the season.
Should Arizona lose on Sunday to the visiting Los Angeles Rams (11-3) and again in Week 17 at the Seattle Seahawks, the team would match its worst record since the franchise moved from St. Louis in 1988.
Arizona has endured a trying season that has included the firing of offensive coordinator Mike McCoy.
Fitzgerald is on record as saying that if he does return to the NFL in 2019, it will be with Arizona -- and it appears the 35-year-old wants Wilks on the sideline.
"I love Wilks," Fitzgerald said. "Great dude. We all play hard for him. That's the team -- not me alone -- speaking on it."
An 11-time Pro Bowl selection, Fitzgerald overcame a slow start due to injury to collect 59 receptions for 645 yards and five touchdowns in 14 games this season.