The spotlight is now on Marcus Mbow as he steps into a pivotal role for the New York Giants.

Mbow, a promising fifth-round draft pick, is set to take over as the starting left tackle this Sunday, filling in for the injured Andrew Thomas. His performance against the Raiders, and potentially in a subsequent start against the Cowboys in Week 18, could significantly influence the Giants’ strategy regarding one of their offseason conundrums.

Jermaine Eluemunor, the current right tackle, is poised to enter free agency at 30, seeking his first major multiyear deal after a stellar season. The Giants’ decision to invest in Eluemunor might hinge on their belief in Mbow’s capability to assume a full-time starting role once Thomas recovers from his hamstring injury next season.

“I just want to get the job done and make a strong impact,” Mbow shared with The Post.

Earlier in the season, Mbow replaced James Hudson, who struggled with penalties, as the team’s swing tackle. Since then, Mbow has impressed off the bench with solid performances on both sides against the Cowboys, 49ers, and Vikings.

Across these three matchups, he has been responsible for just one sack and has allowed eight pressures over 97 pass-blocking snaps.

“That position, in general, just has to be ready to go at a moment’s notice,” offensive coordinator Tim Kelly said. “Being able to go out there and not be noticed is really a testament to him and his ability to prepare, stay locked in. Even though he may not be getting all the reps during the week, being able to understand the game plan and still function at a high level. So, Marcus did a good job with that. He got a whole week to prepare and looking forward to seeing him play on Sunday.” 

Mbow commonly was projected as a second- or third-round pick who inexplicably slipped to the fifth round. The Giants debated Mbow and Cam Skattebo at pick No. 105 and still got Mbow at No. 154. 

“I felt like I would’ve had a chip [on my shoulder] regardless,” Mbow said, “but it definitely affected me and my thought process of myself and how other people perceive me as a football player. Thinking that every day, just thinking ‘OK, that’s what they think of me?’ Cool.’ ” 

In other words, Mbow set out to prove the doubters wrong. 

“Watching myself get better every week over the season, that’s really all it’s about,” Mbow said. “I feel good knowing that I’ve taken a step and I have to keep going from here.” 

There are other ways Mbow could figure into the Giants’ future. He could be a cheap swing tackle again next season — or he could be asked to start at guard (as he did at times for Purdue) if the Giants re-sign Eluemunor and decide to replace free agent right guard Greg Van Roten. 

Breaking up the offensive line — ranked No. 10 by Pro Football Focus and the best unit the Giants have had in more than a decade — is a risk no matter how it is done. 

“I feel like I’m a tackle,” Mbow said, “but if I really needed to [play guard], sure I could. I’ve been trying to bring the most value that I can.” 

The Giants agree. 

“I think the vision for him was always to be a tackle,” interim head coach and offensive play-caller Mike Kafka said, “but he has the athletic ability to kind of do both.” 

First things first. Mbow will face a Raiders defensive line that could be without Pro Bowler Maxx Crosby, who is angry the Raiders plans to shut him down for the final two games in a tank-friendly situation. 

Mbow’s only real hiccup came in Week 3 against the Chiefs, when he replaced Thomas (who was on a pitch count) late in the first half. Why were the results so different when he allowed one sack, five quarterback hits and seven pressures? 

“I went out there in the two-minute [drill] for my first drive and didn’t really expect it,” Mbow said. “That’s never fun, but it is what it is. I’m ready to play this week and excited for the opportunity.” 

One year ago, the Giants had to move Eluemunor to left tackle when Thomas was injured. Two years ago, the season fell apart without an injured Thomas to protect the blindside. 

Now the Giants trust one rookie to protect another (Jaxson Dart) after seeing him sponge information off Thomas, Eluemunor and the other veterans on the offensive line. 

“I’m proud of the effort we put together as a group — a lot of work on and off the field to get where we are,” Mbow said. “Outside of different technique things, they’ve taught me consistency and how to carry yourself in different situations.”