The teenager is believed to have agreed a four-year contract and will arrive from Malmo
Arsenal are set to sign teenage striker Nikolaj Duus Moller.
The 18-year-old forward will arrive from Malmo in a deal which will cost around £450,000 ($583,000).
Moller, a Sweden Under-19 international, had his medical at London Colney on Monday and the deal is expected to be finalised before Monday’s 11pm transfer deadline.
He will then link up with Steve Bould’s U23s squad, rather than Mikel Arteta’s senior side.
Moller will be the latest in a series of signings to bolster Bould’s squad for the coming season, following on from the additions of George Lewis, Tim Akinola and Jonathan Dinzeyi.
The Ghana international – who has a release clause of £45 million (€50m/$58m) – has been a priority target for the Gunners all summer.
Discussions with Atletico have taken place during the past few months, with Arsenal hoping to land the midfielder for a fee less than his release clause, but Atletico have consistently stated that the only way Partey will be leaving this summer is if that clause is activated.
Arsenal have previously indicated that the release is too high, but Goal has been told that stance has now changed and Arsenal are willing to meet the clause and have indicated such to La Liga, who hold the player’s registration.
Speaking about possible incomings after Sunday’s 2-1 win against Sheffield United, boss Mikel Arteta reassured fans that the club would be doing all they can to add to the squad before Monday night’s deadline.
“What I can guarantee is that we are doing our maximum for that to happen, whether we are going to achieve it or not, I don’t know,” said the Spaniard, when discussing the possibility of bringing in new signings.
“I cannot discuss the players that we want but we recognise certain positions that we believe we are short in. First of all in numbers and then adding different qualities to complement each other and this is what we are trying to do.
“I always try to be really honest and clear. Believe me that the ownership, the board, myself, are doing everything we can to maximise the resources we have to improve the team and to sustain and keep the players that are in this club to make this club successful.
“I have 100 per cent backing from them. It’s not just words, it’s reality. Whoever knows me, if it wasn’t like that I wouldn’t say it but I say it because I feel it and it’s true.”
Arsenal are still working on deals which will see Matteo Guendouzi, Sead Kolasinac and Lucas Torreira leave before Monday’s deadline, while Roma are exploring the possibility of signing Sokratis.