Celtic are poised to bid again for Stuart Armstrong once the League Cup semi-finals are out of the way.
The Tangerines should expect another call from Parkhead before the transfer window closes at 11pm on Monday.
By then United will have faced Aberdeen in one semi and the Hoops come up against Rangers in the other.
Celtic had an offer for the Tannadice midfielder – believed to be around £1.5 million – rejected by United on Thursday, along with a lesser bid from English Premier League club Burnley.
Manager Ronny Deila, though, is determined to go back in for the former Scotland under-21 captain.
With the Tangerines looking for around £2.5 million it could be that the Celts offer that but look for their pre-contract signing Gary Mackay-Steven to be thrown in as well for that price.
Losing two of their top talents would be a massive blow to United at such a crucial stage of the season and manager Jackie McNamara would be left with little time to do some buying of his own before the window slammed shut.
