The Raiders have signed or re-signed 22 free agents since mid-March. Jordy Nelson remains that school’s biggest fish.

The former Green Bay Packers receiver inked a two-year, $15 million deal with $13 million guaranteed. He’s the most recognizable on the massive signings list, and prompted the release of Michael Crabtree, a popular and productive, yet mercurial talent who signed with Baltimore.

It doesn’t matter that Nelson’s nearly 33, coming off a disappointing statistical season by his standards. Expectations surrounding him remain high.

Count head coach Jon Gruden among Nelson’s biggest fans. Armed with intelligence from receivers coach Edgar Bennett – he worked with Nelson in Green Bay – and experience covering him as a broadcaster, Gruden has great confidence Nelson can positively impact the Raiders’ on-field product and locker-room culture.

“He can still run,” Gruden said last week at the NFL owners meetings. “He’s a guy we can put on the backside of (triple receiver formations). He can win at the line of scrimmage against press coverage. He’s good after the catch.

“He brings a lot of ‘it’ factor we need. He’s unselfish. He’ll block. He’s excellent at uncovering in scramble drills. His work ethic and consistency is something that will benefit our football team. He’s one of the free agents who will play a huge role for us.”

Gruden expects Nelson to be an asset to 23-year old standout Amari Cooper. Gruden expects him to be a tone setter throughout the offense, and help establish heightened levels of accountability throughout that unit. Gruden also expects excellence working with Derek Carr despite just 53 catches for 482 yards (9.1 ypc) and six touchdowns last season in Green Bay.

“We’re not playing fantasy football,” Gruden said. “We know his production fell off. So did (the production of) Davante Adams and Randall Cobb. So did the Packers offense when Aaron Rodgers went down.”

Gruden has a point. Nelson had 60 percent of his receiving yards and all of his touchdowns in six games before Rodgers was lost with a broken collarbone.

The Raiders believe Nelson will fit in well and enhance the team while essentially taking Crabtree’s place (and paycheck) on the Raiders roster.

“’Crab’ was a good player, no doubt,” Gruden said. “With a lot of receivers, sometimes a change of scenery is a good thing. I think Crab’s in a good place. I think this is a good place for Nelson.