West Ham assistant manager Billy McKinlay has paid tribute to Thilo Kehrer.
The Germany defender has joined AS Monaco on-loan with the option to buy.
Ahead of their FA Cup tie with Bristol City, McKinlay said: "Thilo Kehrer had a good 18 months with us. He was a significant part of our success last season in the UEFA Europa Conference League win.
"This year, he's probably not had as much game time as he would have liked and it's been difficult for him in that regard.
"It's a good opportunity for him to go to AS Monaco and get some playing time. We've been delighted to have him at West Ham United."