Mason Greenwood thanked Getafe supporters in what appeared to be a goodbye message after spending the season on loan at the LaLiga side.
Greenwood, 22, joined Getafe on loan from United in September after a criminal investigation into his alleged attempted rape that was closed by prosecutors.
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He last played for United in January 2022 after he was implicated in controlling and coercive behaviour and assault relating to a woman after images and videos were posted online.
Greenwood scored 10 goals in 36 appearances for Getafe this season, and while his future remains unresolved, he said the campaign had come to a "bittersweet ending" following their 2-1 defeat to Mallorca.
"Incredibly grateful to the Getafe family and fans for an amazing season, thank you for making me feel welcomed and one of your own. I enjoyed every second, alongside my team-mates and club," Greenwood said on Instagram.
"A bittersweet ending, but it was a pleasure to play for you, I wish you all the best."
It comes after Getafe president Angel Torres said he expected the forward to remain at the Spanish club.
"I think we're 92% today that he's staying. Nothing has changed, we're dependent on Manchester. There will be no quick news. The idea is that he stays, but it depends on Manchester," Torres said after their final game of the season.
United co-owner Sir Jim Ratcliffe said in April that no decision had been made on Greenwood's future at the club, although sources told ESPN that a permanent departure in the summer remains the most likely outcome.
Information from ESPN's Adriana Garcia contributed to this report.