The Red Devils signed the Serbian midfielder in a £40m deal from Premier League champions Chelsea on Monday evening.
Matic was part of Jose Mourinho’s Chelsea team that won the top-flight crown and the EFL Cup in 2014-15.
Now the 29-year-old will be tasked with helping to transform Mourinho’s Manchester United side into title winners after sixth-place finish last term.
The Manchester United manager confirmed earlier this month that De Gea is set to remain at Old Trafford despite being linked with Real Madrid.
And the Spanish shot stopper was quick to welcome Matic to the Manchester United family on social media following his big-money move.
De Gea posted the above photo and wrote the following caption: “Welcome to the @manchesterunited family and happy b’day Nemanja Matic! 🎂”
Manchester United have signed Swedish defender Victor Lindelof in a £30.7m deal from Portuguese champions Benfica.
The Red Devils have also added Everton striker Romelu Lukaku to their squad in a £75m transfer.
The 20-time English champions finished in sixth place in the table last season but won the EFL Cup and the Europa League.
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