The transfer window often opens unexpected doors, and every rumour sparks debate. Premier League fans are well aware that West Ham United need to strengthen their squad, especially in goal. The

Tottenham Hotspur have signed forward Mohammed Kudus from West Ham United on a long-term contract, the North London club said late on Thursday.

BBC Sport looks at why new boss Thomas Frank wanted to add him to his squad – and why the transfer is a rare move for the north London outfit.