The Italy international wasn’t involved in United’s 3-1 victory over Bournemouth at Vitality Stadium on Sunday afternoon in the club’s Premier League opener.
Darmian is facing a battle for a first-team spot this season with Luke Shaw fit following his leg break and Antonio Valencia impressive against the Cherries.
However, the 27-year-old was more concerned with his girlfriend as the versatile defender sent birthday wishes to his Italian partner Francesca on Tuesday afternoon.
Darmian posted the above collage of photos on his Instagram page and wrote the following caption:
“Happy birthday my love @francesca_ele_cormanni ❤ miss you”
The Italian full-back moved to United in a £12.5m deal from Serie A side Torino last summer under Mourinho’s predecessor Louis van Gaal.
Darmian endured an injury-hit first season in the Premier League under Van Gaal.
The Red Devils are top of the Premier League table following a 3-1 victory over Bournemouth on the south coast at the weekend.
United will host Southampton at Old Trafford in their next Premier League fixture on Friday night.
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