Boro have lost their last four npower Championship games and have slipped six points adrift of Leicester, who occupy the final automatic promotion place.
Mowbray admits he could yet make an emergency loan signing, but only if it significantly added to the strength of his squad.
He told the club's official website, www.mfc.co.uk: "If there was a player we thought would make a difference and we could afford, we would be in the market.
"We have got enough footballers - if anything, we have got too many.
"It's no good adding another one unless he's an exceptional player who can make a difference, and generally teams are not in the business of giving exceptional players away."
- Sports & Recreation