When the Seahawks signed Mychal Kendricks before Week 2, we figured it could be a really short marriage or else one that was interrupted by a suspension that lasted for as long as half the season.

The Hawks fortunately got three good games out of Kendricks while K.J. Wright was out, and then the NFL went the overly harsh route of suspending Kendricks indefinitely — which typically means beyond the season.

But, thanks to the doggedness of Kendricks and Pete Carroll, the linebacker will be back for the final month of the season and the playoffs after the NFL finally picked a definite suspension: the eight games we originally thought he might get.

So the Hawks will get Kendricks back for the December games against Minnesota, San Francisco, Kansas City and Arizona. That will be some great depth, with Kendricks and Barky Mingo options alongside Bobby Wagner and K.J. Wright (assuming all are healthy in December).

Kendricks played well before the suspension, tallying 13 tackles and two sacks in three games. Ken Norton will have to figure out how to rotate him and Mingo in December.

Kendricks, 28, is scheduled to be sentenced Jan. 24, facing up to three years in prison for insider trading. There’s a slight chance he might get more like 15 months, which would mean he would miss just the 2019 season — and the Hawks might be willing to re-sign him once he were out of prison.

Some think he could get just probation, though that seems unlikely based on the standard rulings in these cases. Kendricks and the Hawks surely would love it if he did, obviously.

He seems more likely to get closer to the standard minimum of 30 months, which would put him out of NFL action until 2021, when he will be 31. It’s tough to see the Seahawks or any team being interested at that point — few players come back after missing that much time.

For now, at least the Hawks know he will be with them deep into January. And that’s good news.

Meanwhile, the release of Brandon Marshall was not surprising. The 34-year-old had fallen to fifth in the receiver rotation — with no special-teams value.

David Moore has been the revelation he appeared to be in training camp, and Jaron Brown is the solid No. 4 (though overpaid to the point that he might not be back in 2019, when he is due $2.75 million).

We dismissed Marshall’s signing in May, thinking he would not make the team. But he had a good summer and served as a strong mentor for some younger players.

The Seahawks should regain a little over $537,000 in cap space by cutting him.

Marshall’s departure could be paving the way for the return of J.D. McKissic next week, with Malik Turner coming up from the practice squad this week.

As the trade deadline passed Tuesday, the Hawks stood still, as expected. They didn’t have much cap space and probably are saving what they have for extensions in December.

A couple of moves tangentially connected to the Hawks though: Detroit traded Sea Lion Golden Tate to Philadelphia, and the Rams acquired Dante Fowler from Jacksonville. The Seahawks will see the Rams in L.A. for a big rematch in a couple of weeks.

Also, the Packers traded safety Ha-Ha Clinton Dix and running back Ty Montgomery, so the Hawks won’t see those players when the teams play in Seattle in Week 11.