West Ham United manager Slaven Bilic has hailed new signing Andre Ayew as a "game changer" following his club-record move from Swansea City.

The 26-year-old completed his switch to the Olympic Stadium earlier this week in a deal worth £20.5m, eclipsing the £15m sum paid for Andy Carroll.

Bilic described the Ghanaian international as a "top player" and believes that he will add quality to the team as the Hammers look to improve on an impressive 2015-16 campaign.

"He adds more quality. We had a really good season. Some people say it was unbelievable, most say it was a really, really good one. So we didn't have the need to start from the bottom and change all the players although in football you are always trying to improve your team - and there are no yesterdays in football. He came to England and did a really good job. He scored 12 goals and played in different positions. He can be a game changer," Bilic told reporters.

"We lost some players who were on loan to us - Victor Moses, Emmanuel Emenike, Alex Song - and one player that we didn't want to lose - James Tomkins - and we wanted to replace them with what we hope are better players. And I'm sure Andre is one of them. He is a top player, he is a winner. He played for a long time at Marseille, where you have to be a strong character because the pressure is there 24/7 week in, week out, and he coped with that.

"And he wanted to come - you want players who want to come to West Ham. The players on our list were also on the list of clubs bigger than us and sometimes you have to convince a player to come here. But he was very excited and we are glad."

West Ham will begin their new Premier League campaign against Chelsea on Monday night.