Sunderland may not find out until the end of the week if their pursuit of Derby County striker Chris Martin has been successful.
Martin is currently in Dubai with the rest of the Derby County squad taking part in warm-weather training.
The Rams squad is not due back in the country until Thursday, with Martin mulling over his decision whether to join Sunderland.
Sunderland's hierarchy are understood to be relaxed about the situation, with work ongoing on transfer business. Championship rivals Reading are also interested in the striker.
Coleman revealed after the Hull City win that Sunderland had a deal in place with an unnamed club and was waiting on a decision from a player, understood to be Martin.
Coleman said: "We thought that something was over the line but at the minute it is not. We have got a deal with a club and we are waiting for an answer and a decision from a player."
Reading boss Jaap Stam has suggested Martin remains a possibility for the Royals this month.
He told GetReading: "Chris Martin has been mentioned with us as well.
"Hopefully we can look at several options to make a choice and we are looking for the type of player where we need to be certain if he does come in he can make a difference."
Derby County boss Gary Rowett said: "We have some strong interest in him [Martin], and Sunderland are one of those teams, but until the player decides he wants to go somewhere and signs on the dotted line, whether that is a loan or a permanent deal, then he is our player."