West Ham comprise signed Czech Republic midfielder Tomas Soucek from Slavia Prague for 21m euros (£19.1m).
Soucek joined the Hammers on mortgage in January nonetheless has now agreed a four-year deal.
The 25-year-frail has scored three instances within the publish-lockdown interval as the Hammers ensured security and a ninth successive Premier League season with a game to spare.
“Soucek has been a terribly staunch fit for us,” supervisor David Moyes acknowledged.
“When I came in, I talked about wanting one more midfield participant, to relief Declan Rice and Be aware Noble.
“He’s a famous lad with very staunch physical capabilities and has scored some really vital goals, in opposition to Chelsea, Newcastle and Watford. We’re ecstatic he’s going to be a West Ham participant for a staunch interval to realize.”