Morata was shown leaving Atletico’s medical clinic on Sunday morning, with the 26-year-old giving a thumbs up and telling reporters, “everything has gone well”.
Atletico have not made any official statement but Morata spoke to reporters at Madrid’s Barajas Airport, after landing in the early hours of the morning.
“I’m very happy, I have been waiting for days,” he said. “I am looking forward to everything being closed so I can start training with my teammates.”
Morata spent two years in Atletico’s youth ranks as a teenager but later joined their city rivals Real Madrid in 2008, where he enjoyed two separate spells either side of a move to Juventus.
Some of Atleti’s fans have not forgotten Morata’s links to Real, with a minority even chanting against his arrival during the team’s La Liga victory over Getafe on Saturday.
“Their opinion is respectable and people can say what they want,” coach Diego Simeone said after the match. “I look for players that serve the club and the team.”
After an impressive start at Chelsea, Morata lost form and confidence, with coach Maurizio Sarri admitting last week the Spaniard had requested to leave at the start of this month.
Morata will bolster Simeone’s options up front, which already include the in-form Antoine Griezmann and Diego Costa, who is expected back from injury next month.
Croatia’s Nikola Kalinic, who joined Atletico in August, could be allowed to leave.
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