However, McLeish fears he is still short quality-wise to tackle the Premier League and wants to keep adding to his squad.
The former Rangers boss bolstered his squad on Thursday after bringing in ex-Liverpool full-back Gregory Vignal on a one-year deal.
"We are not equipped for the Premier League as things stand now. We still need three more players, at least," explained McLeish.
"It's downright bad luck that we have had some injury problems. That's no one's fault. But it has to be realised that if this team is to stay in the Premier League we need more quality.
"I will endeavour to do my very best and draw on all my experience to keep us in the Premier League, but we are definitely a little short of investment."
Man Utd 2/9, Draw 9/2, Birmingham 16/1