Sheffield United boss Chris Wilder is mum regarding any transfer speculation.

The experienced head coach refused to be drawn on Ben Brereton Diaz's impending move to the club.

The 24-year-old is heading back to England after a move from Blackburn Rovers to Villarreal has not worked out as expected.

"No I can't tell you anything really and I'm not going to," Wilder said when asked about Brereton Diaz by reporters.

"There are ongoing things, ins and outs. As the majority of clubs are talking about at this part of the year.

"Until we get things over the line and announced ... I've been part of it in the past when all come out and say this and that and it doesn't work. We're still working on some targets that will hopefully aid us in the second part of the season.

"Some good work is being done and we're close. I think you all understand the situation that I'm in. What I will is that we're close. Close on a couple coming in and close on a couple going out. The situation we want to get to is to pick up some positive results in January, starting on Saturday, and getting some players back from injury, which I'm sure we will do. And the squad looking a lot stronger when the window shuts at the end of January. And I'm 100 per cent certain we will do."