Chris Coleman has revealed that Sunderland chief executive Martin Bain has not been able to guarantee additional funds to strengthen the squad in January.
The Black Cats were relegated from the Premier League at the end of the 2016-17 campaign and currently languish in the Championship dropzone with two wins all season.
Coleman, who replaced Simon Grayson as manager in November, has won one and lost two of his three games so far and, following his exploits with Wales, has reinvigorated the club's fanbase.
However, the 47-year-old admitted that the upcoming transfer window is unlikely to bring heavy investment in the squad and hinted towards making loan signings in January.
Coleman is quoted by the Sunderland Echo as saying: "Martin [Bain] was brutally honest with me and said there is no money guaranteed for January. Depending on if we do lose a player or receive money for a player or players, then it's very possible that we can reinvest but that's not to say there's not going to be nothing either.
"I wasn't promised a transfer kitty in January to go and buy A, B and C. He was brutally honest with me - there may be no money in January to go and reinvest but that doesn't mean we can't go and strengthen the squad with some loan deals.
"I'm OK with that - as long as there's transparency. The worst thing you can do is lie to the supporters and say there's money if there's not. I came here on the understanding that January, there's possibly not any money to invest in the squad. I know where I stand but that's not to say something couldn't happen."
Sunderland currently sit second from bottom in the Championship table, two points from safety.