Diego Costa - who joined from Chelsea - will be available to play for Atletico following La Liga's winter break, leading to claims Griezmann could then move on with Barcelona reportedly preparing a €100 million bid.
"I have not made a decision". If Atletico are to progress then they will need to beat the Italians tonight and hope that Griezmann finds his scoring boots.
Griezmann has endured a difficult season at Atletico and was whistled by supporters as he was substituted during Saturday's 0-0 draw with Real Madrid at the Wanda Metropolitano. "I do not exclude anything".
"Although I am missing titles, here I have everything to be happy". The Welsh international left Spurs for Real Madrid in 2013.
United's chase of French forward Griezmann was one of the talking points of the early weeks of the summer transfer window, with Jose Mourinho having identified the 26-year-old as an ideal addition to his attacking ranks at Old Trafford.
"But the important thing for our club is always to improve". The Italian side have won two games and drawn twice this campaign, with their last contest with Chelsea ending with the side hammering the Blues 3-0. There are games where I don't even get one shot on target and that's my problem.
Players have clearly struggled to adapt to their remote new home, nearly 20km northeast of the Calderon.
Paris Saint-Germain are reportedly interested in signing Antoine Griezmann, while Roma are said to be keen on Javier Pastore.
The Red Devils were one of the busiest clubs last summer as they brought in Romelu Lukaku, Victor Lindelof and Nemanja Matic. People have shown great appreciation for him.
"I respect the opinion of Antoine's brother, the same as other people's opinions", he said.
Asked which Atleti player would he like to sign for Roma, Monchi did not mention Griezmann.
"I knew [Di Francesco] from before, and I remember the derbies", he said. "They have a lot".
"He is an extraordinary footballer".