Leicester have agreed to sign centre-back Caglar Soyuncu for £19m from Bundesliga side Freiburg.
The Turkey international, 22, was a target for Arsenal earlier in the summer but will now join the Foxes.
Soyuncu is waiting for a work permit before the deal can be completed.
When completed it will take Leicester’s spending on centre-backs to £29m on deadline day.
Filip Benkovic earlier arrived from Dinamo Zagreb for £13m after signing a five-year contract.
Leicester’s initial interest in the duo was thought to be paving the way for Harry Maguire’s exit to Manchester United.
But the Foxes fought to keep hold of Maguire and demanded that United pay a world-record fee for a defender if they wanted to land him.
Maguire will now have Soyuncu and Croatian Under-21 man Benkovic for company at the back until at least January.
Freiburg battled Sevilla and Besiktas to sign Soyuncu from second-tier Turkish outfit Altinordu for just £2.4m in 2016.
Fifteen-cap Soyuncu has gone on to display an all-round defensive game to rival the Bundesliga’s best blockers – with comparisons drawn to Mats Hummels.
His signature takes Leicester’s spending past the £100m mark this window after their earlier deals for Ricardo Pereira, Jonny Evans, James Maddison, Danny Ward and Rachid Ghezzal.