England international goalkeeper Fraser Forster joined Southampton from Celtic on Saturday, penning a four-year deal believed to be worth £10 million (12.5 million euros, $17 million).
The 26-year-old, who was part of the England squad at the World Cup in Brazil, began his career with Newcastle United, and had loan spells at Stockport County, Bristol Rovers and Norwich City before joining Celtic in 2010.
Meanwhile, Koeman also said Southampton had had a bid -- believed to be in the region of £4.5m -- rejected by Leeds for 20-year-old right-back Sam Byram.
