SEATTLE — Hoping to add a veteran presence to a receiving corps lacking experienced depth — and maybe also hoping he can reclaim the form that has made him one of the most productive players at his position in NFL history — the Seahawks have agreed to terms with Brandon Marshall.

The 34-year-old, who is the 23rd-leading receiver in NFL history with 12,215 yards, will likely sign a contract with Seattle by Wednesday, a league source confirmed to the Seattle Times.

Marshall broke the news himself of his agreement with the Seahawks, posting pictures on Instagram Tuesday wearing a Seattle jersey.

It was reported by ESPN’s Adam Schefter that Marshall agreed to a one-year deal with Seattle that with incentives could reach $2 million. Because Marshall is a vested veteran of more than 10 seasons, the minimum salary he can make is $1.015 million.

Marshall visited the VMAC three weeks ago when the offer was apparently made and is signing with Seattle after apparently having waited to see if anything else might also materialize. The signing may not become official until Wednesday as Seattle will also have to make a corresponding roster move to waive another player to make room on the team’s 90-man roster.

Marshall was released by the Giants last month after having signed a two-year, $12 million deal with the Giants prior to the 2017 season. He was waived with a failed physical designation following ankle surgery and a major part of his visit to the VMAC earlier this month included a physical allowing Seattle to get a sense of where Marshall is health-wise. Seattle apparently feels comfortable enough to give him a shot.

Before hurting his ankle in the fifth game last season, Marshall caught just 18 passes for 154 yards and no touchdowns, all lows of an NFL career that dates to 2006 — Marshall was already out for the year when Seattle beat the Giants 24-7 in New York last October. The Giants then also had a coaching staff overhaul, firing head coach Ben McAdoo and replacing him with Pat Shurmur.

At the least, the Seahawks are thought to believe the 6-4, 229-pound Marshall can help replace the red zone production lost when Jimmy Graham left via free agency, signing with Green Bay.

But Marshall’s contract also makes it far from a guarantee that he makes the regular-season roster and Seattle appears to view him as most likely to play in a situational role — Marshall has just 77 receptions for 942 yards and three touchdowns in 20 games in his last two seasons.

But then, the Seahawks won’t argue if Marshall can also rediscover the form that has made him one of the most productive receivers of this generation — he has eight 1,000-yard seasons and has been named to the Pro Bowl six times, doing both most recently in 2015 when he had 109 receptions for 1,502 yards and an NFL-high 14 touchdowns. He also holds the NFL single-game record for receptions with 21 while playing for Denver in a game against the Colts in 2009 and is tied for third with 18 in a game for Denver against the 49ers in 2008.

Seattle will be the sixth team Marshall has played for after entering the league as a fourth-round pick of the Broncos in 2006.

The Seahawks also made a run at signing Marshall in coach Pete Carroll’s first year in 2010 when he was a restricted free agent, making a visit to the VMAC in which it was reported he arrived to the facility via a seaplane. He was ultimately traded to Miami, later telling reporters that at that time he didn’t think the Seahawks were the right fit.

But Marshall’s age and recent injury history left him fewer options this time around.

He also has a history of finding himself embroiled in legal issues and locker room controversy.

An SI.com story in 2014 reported that Marshall “has been named in at least eight separate incidents of violence against women since he was drafted in 2006. But none of those incidents led to a criminal conviction (several didn’t result in any charges filed), and the NFL suspended him only once, for one game.”

It was also reported by ESPN that while with the Jets in 2016 Marshall had a “heated verbal altercation” with teammate Sheldon Richardson — who spent last season with the Seahawks before signing with the Vikings in March.

Marshall has also revealed that in 2011 he was diagnosed with borderline personality disorder, something he wrote about at length in a story for The Players’ Tribune last year.

Marshall’s history and age would seem to run counter to the idea that the Seahawks are rebuilding and hoping to do so with a “quieter” locker room.

But then, Carroll and general manager John Schneider have each resisted the idea that the team is indeed rebuilding, and Marshall becomes the fourth player 30 years or older to sign with Seattle this offseason, the others being 40-year-old kicker Sebastian Janikowski, 34-year-old defensive tackle Tom Johnson and 30-year-old tight end Ed Dickson.

And the Seahawks are noticeably light on experience at receiver following their projected top three of Doug Baldwin, Tyler Lockett and free-agent signee Jaron Brown.

While those three have combined for 666 catches (Baldwin 443, Lockett 137, Brown 86) the rest of the receivers on Seattle’s history have a combined 27 — Tanner McEvoy with 14, Amara Darboh eight and Marcus Johnson five, with the other five receivers on the roster yet to make an NFL catch.

Marshall has 959.