Allen said: "The budget available to Paul to spend on the recruitment of new players was affected by disappointing attendances last season and the poor turn-out for the two concerts staged at the stadium over the summer.
"We averaged crowds of just over 6,000 last season, which was around 1,000 down on the figure we budgeted for. This was disappointing when you consider the fact that we were in the top three for most of last season, playing some attractive football.
"We expected to attract more revenue than the amount received for the two concerts and the historic debt associated with the relocation to the new stadium four years ago also has to be serviced.
"The knock-on effect of the loss of revenue is that we have had to do some prudent house-keeping to ensure that the problem is kept in check."
Allen has appealed to supporters to get behind the management staff and the players as they prepare for life in Sky Bet League 1. He said: "We recruited players last summer with one eye on League 1 and other players brought in during the course of the season were also signed in the knowledge that they would be able to make the step up.
"We have a squad of players who are more than capable of competing effectively in League 1 and I would urge you to give them your full support."