He has also reiterated that retaining the club's current crop of talent is just as important as new additions.
He said: "Do we need to buy players? Hopefully, by the end of August someone will come in who will help but if that is not the case then we know what we have got in the team and we will have to fight.
"We know the situation at the moment. We cannot spend money like other clubs. That is sensible, even if it is not very popular.
"But at least we have been able to keep our best players. If we cannot sign new players we must keep the ones we have.
"It has been the same with myself, with Tim Cahill, Marouane Fellaini and so many other players in previous years. It is important that we stayed, now and for the future.
"If someone comes and buys the club then it is a different story but at the moment the club cannot make stupid signings that might put us in trouble for the next few years."