On Sunday, Coleman was confirmed as the replacement for Simon Grayson after opting to resign from his job with Wales, and he has been given the task of moving the Black Cats off the bottom of the Championship standings.
Sunderland have already been linked with loan moves for Liverpool duo Danny Ward and Ben Woodburn, but Coleman has insisted he has not been promised a budget to bring in players during the January transfer window.
The 47-year-old is quoted by the Sunderland Echo as saying: "The January transfer window will depend, maybe we will have to regenerate some cash ourselves. I am under no illusions. We have got what we have got, I haven't been promised a huge transfer kitty that I can go and splash cash, it is not that.
"So, I knew that before I walked through the door. I know the players we have here, we can improve the players we have here, yes we need to reshuffle the squad, clearly.
"I am not saying anything that nobody knows already. I am not going into the January transfer window with millions of pounds to spend but it can be something to invest."
Coleman will hope to make a winning start to his reign when Sunderland travel to the West Midlands to face Aston Villa on Tuesday night.