Roy Keane has refused to comment on any interest in Kenwyne Jones, while Sunderland winger Carlos Edwards is out for four weeks.
Southampton striker Jones has been linked with a £5million move to Sunderland, having also been tracked by Derby County.
Black Cats boss Keane is hoping to bring in more players before the close of the transfer window, but shied away from admitting an interest in Jones.
"I don't think it's fair to be commenting on players that we haven't been given permission to speak to," said Keane on Sky Sports News.
"I've said for weeks, and I will continue saying it, we are probably looking to add one or two players to the squad and that will continue over the next week or two.
"But I'd rather not comment on certain players at certain clubs because they're still under contract there."
Keane did confirm that Trinidad & Tobago winger Edwards will miss the next month with the hamstring injury sustained against Birmingham City in midweek.
"It's a big blow for us, Carlos is a big player for us," continued Keane. "He gives us plenty of width and can beat a man.
"Carlos is out for four weeks we expect - that's part of football, other clubs are having injury problems.
"We have other players to come in and hopefully they will do as good a job as Carlos."