Nottingham Forest brought McAtee in as one of Nuno Espirito Santo's earliest signings, paying £30million for the former England Under-21 international.
With the Hammers having sold Mateus Fernandes to Tottenham Hotspur for £85million, they now see McAtee as the ideal replacement in the middle of the park.
New director of player recruitment Nils Koppen has long admired McAtee and has reportedly ranked him top of West Ham's midfield wishlist.
McAtee's minutes were limited last season, but that has done little to dent his standing at the City Ground.
If anything, the arrival of new manager Oliver Glasner has strengthened Forest's resolve to keep him, given his preference for a two-man attacking midfield that could see McAtee line up alongside Morgan Gibbs-White, reports the Daily Mail.
McAtee's stock rose further when he helped England's Under-21s lift the European Championship a little over a year ago.
Forest see shades of that trajectory in McAtee given several of his former Under-21 teammates - Elliot Anderson, Jarell Quansah and James Trafford among them - have since broken into England's senior World Cup squad, and the club are reluctant to sell before his value climbs higher still.
Even so, having banked significant funds from recent departures, West Ham are ready to test Forest's resolve as they aim to make a further statement signing in their push for an immediate top-flight return.
Having arrived at the City Ground with a strong academy pedigree from Manchester City, McAtee's growing importance under the club's new coaching setup only strengthens Forest's reluctance to let him go cheaply.
West Ham United's interest forms part of a broader rebuild under Graham Potter, who is keen to move decisively after missing out on several other targets earlier in the window.
Forest, though, have shown little inclination to budge on their valuations elsewhere in the squad this summer, and McAtee's situation looks unlikely to be any different.
Any deal is likely to hinge on West Ham matching, or bettering, the fee Forest paid to sign him last year, given how central he has become to Glasner's plans heading into the new season.