The 24-year-old midfielder, valued at 48 million euros (40 million pounds), has emerged as a prime target for the Red Devils, who see him slotting seamlessly into Ruben Amorim's 3-4-2-1 system.
Dortmund have endured a torrid season in the Bundesliga, slumped in 11th place after losing seven of their last 11 league matches.
Their only lifeline to Champions League football next term hinges on lifting the trophy this season, a tall order with Barcelona standing in their way in the quarter-finals, despite a spirited victory over Lille in the last round.
The financial strain of missing out on Europe's elite competition could force Dortmund to cash in on a big name, and United are ready to pounce.
BILD has reported that Dortmund are reluctantly open to offers for key stars like goalkeeper Gregor Kobel, winger Jamie Gittens, or forward Karim Adeyemi. However, United have set their sights on Nmecha, a player the Black and Yellow would typically deem untouchable.
The report claims the Red Devils are preparing a hefty 48-million-euro bid, a move that would net Dortmund a tidy profit on the 30 million euros they shelled out to Wolfsburg for him in 2023.
"Felix is a difference-maker," a source close to Dortmund told BILD, underlining the club's hesitation to let him go. Yet, with finances dictating tough calls, and Nmecha potentially tempted by a switch to Old Trafford, a deal isn't off the table.
Adding intrigue, Nmecha holds an English passport from his Manchester City academy days and represented England at youth level before pledging allegiance to Germany, where he's earned three senior caps.
Nmecha, sidelined since January with a knee ligament injury, has recently returned to light training, a boost for both Dortmund and his suitors.
On X, Dortmund's official account confirmed his progress, posting: "Felix Nmecha back on the pitch with the squad—great to see him stepping up recovery."
Meanwhile, United's transfer radar remains busy. Sky Germany's Florian Plettenberg revealed on X that the Red Devils have kept tabs on RB Leipzig's Xavi Simons, a versatile attacking midfielder carrying an 80-million-euro price tag. "United have never lost focus on him," Plettenberg wrote, though he noted Leipzig's steep demands could complicate matters.
Bundesliga strikers Benjamin Sesko and Hugo Ekitike also feature on United's shortlist, alongside Sporting CP's Viktor Gyokeres.
Elsewhere, speculation swirls around United's current frontman, Rasmus Hojlund. Gazzetta dello Sport has claimed the Dane could be offloaded this summer, with Napoli's Victor Osimhen emerging as United's top choice to spearhead their attack.
Borussia Dortmund have stepped up their interest in Sunderland midfielder Jobe Bellingham, with a senior delegation visiting the North East on Wednesday to discuss a potential summer transfer.
Schalke 04's rising star Taylan Bulut is attracting growing interest across Europe following a standout 2024 season.
Harry Kane has expressed his delight at securing his first major trophy after Bayern Munich were crowned Bundesliga champions, with the England captain now setting his sights on further silverware.
Brazilian winger Antony has hailed his January loan move to Real Betis as the best decision he's ever made, after a difficult stint at Manchester United.
