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.
Hammers boss David Moyes has previously been linked with Burnley’s James Tarkowski and St Etienne’s Wesley Fofana as he looks to strengthen his defence.
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.
Summer transfer window – key dates and times
The summer transfer window closes at 11pm on Monday, October 5 with a feast of activity lined up on Transfer Deadline Day on Sky Sports News and across our Sky Sports platforms.
A domestic-only window for deals between the Premier League and EFL then runs from October 5 and closes on Friday, October 16 at 5pm. Follow all the news and analysis on SSN and across Sky Sports‘ digital platforms, including with our dedicated Transfer Centre blog.