Manchester United boss David Moyes has been given assurances that significant funds are available to him this month and in the summer.
The club is targeting a left-back and central midfielder, and senior figures at the club have told Sky Sports News that Moyes will receive all the financial support he needs to make any moves.
But Manchester United officials, who have given Moyes their full support and have no plans to appoint a director of football to support transfer activity, will not rush into any panic buys and stress that the availability of top players remains the biggest obstacle.
"We would like to bring people in but are those players available?" Moyes asked after his club's FA Cup defeat to Swansea on Sunday.
"There is an urgency but there's no point in me hyping it up because the players we would like to bring in are probably not available in January."
United have yet to trigger one-year extension clauses in the contracts of Rio Ferdinand and Patrice Evra, who are both out of contract in the summer, and talks have yet to take place with Nemanja Vidic and Fabio who are also free to talk to clubs this month.
Sources at the club say talks will take place, which will include representatives of Wayne Rooney, at the appropriate time and there is 'absolutely no panic' about the current situation.
Sky sources understand that Cardiff are one of at least six clubs to have made a loan inquiry for Wilfried Zaha this month.
Moyes is understood to want Zaha to play more games but no decision has been made on the forward's future as the club assesses Nani's hamstring injury.
