Arsenal manager Unai Emery was in attendance when Atletico Madrid faced Levante in their last La Liga fixture of the season.
It is believed the Spaniard was there to look at Ghanaian midfielder Thomas Partey who has been linked with a purported interest from the Premier League side to sign him this summer recently.
The Gunners want to sign Partey who has a release clause of £43 million as replacement for the departing Aaron Ramsey.
The 25-year-old has had a remarkable campaign for Atleti this season and has also been interesting the Manchester clubs, City and United according to reports in England.
Partey featured 44 times for Madrid outfit in all competitions, scoring three goals and assisting four.
His immense contribution saw Atletico Madrid lift the UEFA Super Cup at the beginning of the season and finished second on the La Liga standings.