Stoke City's £18.3m record signing Giannelli Imbula could leave the club this summer, manager Mark Hughes says.
The 24-year-old Belgium-born midfielder has made just 23 Premier League starts since joining from Porto on a five-and-a-half-year contract in February 2016.
"Sometimes things just don't pan out as you hope," Hughes said.
"It has been a frustration for all parties involved. It's fair to say with Giannelli that things haven't quite worked out."
Imbula became Portuguese football's record signing when he joined Porto in a £15.1m deal from Marseille in July 2015.
"He hasn't quite adjusted to the Premier League," added Hughes.