The Red Devils are believed to have already come to an agreement with Ugarte over personal terms, but a deal for the Paris Saint-Germain midfielder will be difficult unless the French champions lower their valuation.
Luis Enrique's side are believed to be looking for a fee of €70m (£59m) for the Uruguay international, meaning that the Red Devils may be forced to look elsewhere in their bid to bring in a defensive midfielder.
According to the Manchester Evening News, Zubimendi is on Man United's radar, with the Red Devils giving serious consideration to making a move for him this summer.
The report claims that the 20-time English champions are currently monitoring the midfield market, with Adrien Rabiot, who is available on a free transfer, also an option for the club.
Man United 'showing' an interest in Zubimendi
The release clause in Zubimendi's Real Sociedad contract is believed to be €63m (£53m), making him a cheaper option than Ugarte, should PSG stick to their alleged valuation.
The 25-year-old made four appearances for Spain at Euro 2024, including the second half of the final against England, replacing the injured Rodri at the interval.
Zubimendi excelled during his 45 minutes on the field against the Three Lions, further demonstrating his qualities after another impressive season at club level.
The midfielder scored four goals and registered one assist in 45 appearances for Real Sociedad last term, and he featured on eight occasions in the Champions League in 2023-24.
What has Zubimendi said about his future?
Speaking during Euro 2024, Zubimendi revealed that he is "most comfortable" at Real Sociedad and was not looking to leave his Basque club this summer.
"Where am I going to play next season? I'm going to be at Real Sociedad. I have a contract with Real Sociedad and that's where I'm most comfortable," he told El Diario Vasco.
Barcelona and Arsenal are believed to be admirers of the Spaniard, but it appears that both clubs have different priorities during the summer market.
Man United are only believed to be considering making a serious attempt to sign Zubimendi if a deal for Ugarte falls through, but that is certainly a possibility if PSG refuse to drop their asking price.
Zubimendi has made 188 appearances for Real Sociedad since breaking into their first team, scoring eight goals and registering seven assists in the process.