The Whites boss has been able to bolster his ranks this summer, but has been left frustrated in his pursuit of other targets.
Work is continuing to try and bring the necessary bodies into Elland Road, with there now less than a month to go until the transfer window slams shut.
McDermott is hoping to add before 2nd September, and concedes that defensive reinforcements and width in midfield are two top priorities.
He told the Yorkshire Evening Post: "I'm trying. There's no point in me saying what I'm trying to do but I am trying.
"We've got, for example, two young centre-halves (Tom Lees and Jason Pearce) playing all the games because we've only got those two.
"We've got a number of left-backs, but no wingers. We're short in areas."
McDermott, who has seen Leeds open the new season with victories over Brighton and Chesterfield in the league and cup, added: "I'm trying to do what I can with the players I've got and they're doing great.
"We've been without Rudy Austin, El Hadji Diouf and Sam Byram, and they're big players for us, but we've won the last two games and dug out results."