West Ham have completed the permanent signing of Czech Republic international Radoslav Kovac from Spartak Moscow for an undisclosed fee.
Kovac, 29, played nine times for West Ham on loan last season and has signed a three-year deal.
"I'm delighted to be back,'' the midfielder told the West Ham website. "I enjoyed my time here last season and I am very happy to get the chance to come back and compete for a place at West Ham.
"It is great that it is permanent deal and that it is all sorted out.''
Kovac's chances of playing in the Premier League opener against Wolves hinge on him getting international clearance in time.
Manager Gianfranco Zola said: "He is a good player for us. He has got experience, he has got charisma, a good personality and he will be an important player for us.''