Summary:
Sunderland's manager is concerned that the club is being snubbed by transfer targets because of a leak of information.

Full article:
Gus Poyet will investigate what he believes is the source of an internal leak of information at Sunderland. The Black Cats boss was alarmed when asked about his interest in former Chelsea winger Salomon Kalou, now at Lille. ‘I’m going to have to do research on this football club and who is leaking information every week,’ said the Uruguayan. VIDEO Scroll down to watch Gus Poyet discuss Sunderland surviving relegation last year . A worried Gus Poyet: ‘It cannot always be the agent or the player. There’s too much information coming out' Leak: Poyet was concerned at how the information that Sunderland were looking at Salomon Kalou emerged . ‘It cannot always be the agent or the player. There’s too much information coming out and I don’t like it. I’m not going to comment (on Kalou).’ West Ham are set to rival Sunderland for the signature of the £4million-rated Ivorian. Meanwhile, Poyet says a deadline for Liverpool’s Fabio Borini to decide if he wants to rejoin Sunderland is closing in. He said: ‘I think we’re getting close to a final decision either way because it’s been a bit too long. ‘It’s time now that it’s a yes coming or a no as we need to move on.’ In or out? West Ham are set to rival Sunderland for the signature of the £4million-rated Ivorian Kalou . Return: Kalou would be coming back to the Premier League if he joins either club after leaving Chelsea .