Strikers Jermaine Beckford and Tresor Kandol are set to miss Tuesday's trip to Oldham.
The duo, who have 11 goals between them so far this season, were both controversially sent-off during Saturday's 1-1 draw at Gillingham for two bookable offences.
With Tore Andre Flo and Leon Constantine both sidelined through injury, youngster Tomi Ameobi is the only available striker for the trip to Boundary Park.
"We haven't any senior strikers," confirmed Wisey, who is expected to look at the loan market ahead of the game.
"It's not an ideal situation and we'll have a busy few days looking to see what we can do."
Dennis has already stated that he is more than happy with the strikers he has at the club, and he is keen to nurture young Tomi along, but a loan move could be the only way to solve the problem ahead of Tuesday.
United will head for Oldham on the back of an eight-match unbeaten run, the winning start to the season coming to an end with the1-1 draw at Gillingham.
United were reduced to 10 men before half-time when Kandol was sent-off, and Jermaine followed midway through the second period, leaving the remaining nine to perform a terrific rearguard action that almost kept the home side out.
Referee Danny McDermid also booked a number of other Leeds players, Wisey was sent-off at half-time, and the boss said he was sworn it by the match official when he approached him after the final whistle.
"I think it is totally and utterly unacceptable and we as a club will be reporting him," said the boss.
"I have three witnesses who are going to back me up, so well done to the ref, he got the headlines he obviously wanted.
"The ref has sent me off at half-time because I've said something that I shouldn't have done. But it seems there are two different sets of rules."
