Kral joined West Ham on loan from Spartak Moscow last summer and the deal contained an option for the Hammers to sign him on a permanent basis.
The midfielder is due to officially end his loan with the Hammers at the end of June and is set to return to Russia to link up with Spartak Moscow.
He made just one appearance in the Premier League, while he also turned out three times in the Europa League and once in the FA Cup and the EFL Cup.
Kral is now on international duty with the Czech Republic and his national team boss has admitted the 24-year-old expected to play more football, something he also thought would happen.
“We and Alex believed he would play more in England”, Silhavy said at a press conference.
“But on the other hand, at least every day he trained with players who finished in seventh place in the best competition in the world.
“We want to see him and have him with the team for two weeks.”
Silhavy’s Czech Republic have games in the Nations League coming up against Switzerland, Spain, Portugal and Spain again, and Kral will be looking for the game time which eluded him at West Ham.
