The Giants added help for Dexter Lawrence and Leonard Williams. Not a replacement.

A theme of the offseason — fortifying one of the league’s worst rushing defenses — continued Monday with the signing of free agent A’Shawn Robinson.

The one-year deal is worth up to $8 million, but the 2023 salary-cap hit is only about $4 million, a source told The Post’s Paul Schwartz.

Robinson made a strong impression when he visited the team facility on March 20, but the finer points of a negotiation took weeks to be ironed out.

The 28-year-old defensive tackle, who underwent a medical exam during his visit, was sidelined for the Rams by a torn meniscus from late November through the end of last season.

Regarded primarily as a run-stuffer, Robinson is a former second-round pick with seven career sacks in 93 games, including 61 starts (10 last season).

Since free agency started, the Giants have added linebacker Bobby Okereke and defensive tackles Rakeem Nunez-Roches and now Robinson to improve a unit that ranked No. 31 in the NFL last season with 5.2 yards per carry allowed.

“One of the things that concerned me last year was our inability to stop the run,” Giants co-owner John Mara said recently. “It just seemed like it was second-and-2 all the time. And it’s pretty hard to live that way all season. So, I think the players that we added there will help us. If we can consistently stop the run, then we can unleash the pass rush. Those are some of our best players right now.”

Robinson’s addition should not be taken as a sign that the Giants are losing faith in extension talks with Lawrence or are ready to move on from Williams.

In fact, the Giants were looking for a way to lighten the workload on their two studs after Lawrence averaged a remarkably high share (81.7 percent) of the defensive snaps across the 16 games he played last season and Williams logged 81.5 percent or more in eight times while his streak of 114 consecutive games played ended.

After No. 3 defensive tackle Nick Williams suffered a season-ending biceps injury last season, the Giants were short-handed and rotating journeymen Justin Ellis and Henry Mondeaux and undrafted rookie Ryder Anderson.

Nick Williams and Ellis remain unsigned, and a healthy Robinson and Nunez-Roches represent a significant upgrade to the depth chart.

No corresponding contract restructures were required to fit Robinson’s contract, the source said, despite NFLPA records showing the Giants pressed up against the salary cap. Bonuses and incentives account for about half the deal.

With the need for defensive linemen lessened, the Giants might have increased their need for starting-caliber defensive backs ahead of this week’s draft.

The Giants have young safeties Jason Pinnock and Dane Belton and young cornerbacks Cor’Dale Flott and Aaron Robinson competing for jobs to round out the unit with Adoree’ Jackson and Xavier McKinney as opponents adjust to having fewer running lanes.