Alan Smith
Alan Smith says expectations of an immediate impact from Krystian Bielik are unrealisticGetty Images

Former Arsenal striker Alan Smith has warned supporters expecting an instant impact from imminent signing Krystian Bielik that they will have to wait several years before seeing the Polish youngster's best.

The 17-year-old Legia Warsaw midfielder is close to moving to the Gunners over Hamburg during the mid-season window having caught the eye of several of Europe's biggest clubs, with a reported fee of £2.6m expected to secure his services.

Bielik has already spent time with Arsenal manager Arsene Wenger, after meeting the first-team squad in north London earlier in the season, and seemingly has his heart set on a move to the Premier League despite an official announcement having not yet been made.

The addition of Bielik would be the latest in a string of young players to move to Arsenal in recent years, with Wenger partial to bolstering the club's youth ranks instead of making significant signings in the transfer window, and therefore Smith expects the player's impact to be delayed.

"It's a classic Arsene Wenger signing, he's one for the future," he told Sky Sports News. "He's a big lad, over six-foot tall and a defensive midfielder, the kind the team needs, but he is 17 years of age.

"He is not going to slot into a Premier League team straight away. So again you are looking at a year or two ahead when he could possibly have an impact, so probably not going to have much of an impact not this campaign."

Legia boss Henning Berg added: "He doesn't have any weaknesses. He is strong in size, he has good skills, good understanding, 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."

A deal for Bielik is expected to be confirmed in the coming days and he will become Arsenal's first signing of the January transfer window, with an additional defender also expected to join.