Sunderland boss Sam Allardyce reveals which transfers he is currently working on

Despite the need to boost a squad that finished fourth bottom last season, Sunderland are yet to make any inroads into the transfer market, albeit the window only formally opened last Friday.

However, manager Allardyce has explained the factors behind that, as he focuses on his main targets, who can immediately improve the strength of the starting XI.

"I have not signed any of the free transfers or loan players just yet, because that can be done later on," said Allardyce.

"I'm basically focusing on the top players that I need for the team this year and waiting patiently for those.

"Let's do that first, rather than taking a player here or there, who might be a good one, but we want to get those who can go straight into the team and make an impact.

"Then we'll look around after that and see what we need to bolster the squad and challenge the players that are already here."

Sunderland returned to pre-season training on Monday and underwent an extensive round of testing and conditioning.

The Black Cats squad will fly out to Austria tomorrow for an intense nine-day training camp in the Alps, where they will continue to work on their fitness levels.

"The lads seem to be in good spirits. They've been through the usual start of pre-season testing," added Allardyce to the club website.

"They did have their own programmes while they were away to keep them ready so we can move straight into football practices.

"It's fitness and football at the moment, quite long, but they seem to be coping pretty well."