Mowbray failed to bring his top target, Leeds United forward Ross McCormack, to the Riverside in the summer and admits that he still needs to add a quality attacking player.
"It's not ideal to fill your club full of loan players. I always prefer to sign footballers," the former Celtic manager told The Gazette. "The loan market is good if you get the right one who has the hunger and desire to just come and play football, who has probably been starved of football at the club he's at.
"Up front, we've looked at a different type of player. We have been searching for a footballer who gets into the box but also links the middle to the front.
"Ross McCormack didn't happen, but that type of player - half a midfield player, half a centre-forward, someone who lives off goals but also links up play - that search potentially continues."
Middlesbrough are currently 15th in the Championship.