Legia Warsaw coach Henning Berg is convinced Krystian Bielik can make it at Arsenal.
Arsenal are close to completing a deal for Bielik, who will have a medical with the club on Friday.
Berg hailed Bielik's potential last night, saying: "He doesn't have any weaknesses.
"He is a physical player with good skills, good understanding, a good match mentality and good decision-making in the game. For his age, he is quite far ahead compared to others in his age group."