Slavia Prague right-back Vladimir Coufal will undergo a medical in London on Thursday ahead of a move to West Ham.
Slavia president Jaroslav Tvrdik confirmed the news via social media on Wednesday evening, with the fee reported to be around £5m.
The 28-year-old has won two Czech titles since joining Slavia in 2018 and impressed in his country's 2-1 win over England last year.
If a deal can be made, Coufal will compete with Ben Johnson and Ryan Fredericks - once the latter returns from a hamstring injury - for the starting right-back berth.
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