United manager Simon Grayson is keeping his cards close to his chest as the time continues to tick down towards the closing of the January transfer window.

The United manager has made no secret of the fact he is on the hunt to strengthen his squad in readiness for the second half of the campaign, but is refusing to give away any clues about his possible targets.

So far this month, Danny Pugh made his move permanent from Stoke City, Robbie Rogers will complete a switch from the MSL by finalising an 18-month deal, Maik Taylor has signed until the end of the season, and Premier League midfielders Andros Townsend and Fabian Delph have joined on loan deals.

"We're working hard and there's a lot of calls been put into a lot of people," said Grayson. "We're trying to do things as quietly as possible. We've been linked with a few people, but I'm not going to comment on any speculation.

"There's a couple of clubs we've spoken to who are involved in the FA Cup this weekend and may look to use one or two of their fringe players. If they go out that might make it easier.

"We're in the hands of others to a degree with certain things, but that doesn't go to say we aren't working hard. There's players we're looking at it who are available depending on certain situations.

"We're looking at all sorts because there's money to utilise. Whether that's transfers, free transfers, or loans to the end of the season…we're looking to bring the quality that we would like and it isn't always as easy people think.

"You only have to look at the deals that have been done so far. The Premiership is so quiet at this moment in time. I think there's £20m been spent and that's not a lot at this stage, but I'm sure it will liven up quickly. Once things move things will trickle down.

"The window is so frustrating for everyone because you seen names linked every day. Some are way off the mark, some are close and some are maybes. It leads people up the garden path at time. It can drive you around the bench."

The window closes on Tuesday and, unusually, the deadline falls on an evening when there is a full Championship fixture programme.

"We've got plenty of time before Tuesday's game, and we'll see what happens and where things go," said the boss.

"It'll be difficult on Tuesday because everyone will have a game.

"Ideally you want it all doing by Monday night so you can concentrate on the game, but if it means going down to the last few hours because someone has become available then that's what you have to do."