West Ham have signed Spartak Moscow's Alex Král on a season-long loan with an option to make the move permanent.
The 23-year-old joins his compatriots and former Slavia Prague teammates Tomáš Souček and Vladimír Coufal at London Stadium.
"He will provide good competition in the centre of midfield," West Ham manager David Moyes told the club's website.
"He is another young, talented player who we feel has a big potential and will be capable of adapting to the demands of the Premier League."
"We've brought him in on loan initially and, hopefully, over the course of the season he will make a valuable contribution, particularly with our busier schedule of fixtures," Moyes added.
"Alex is another established international player with the Czech Republic, and we hope he has similar characteristics and hunger to that of Tomas and Vladimir."
Born in the eastern Slovak city of Kosice, Kral has scored two goals in 22 games for the Czech Republic national team, with whom he reached the Euro 2020 quarter-finals.