He said: "I think players, deep down, have a realisation of how they are playing and, to me, the best way to get confidence back is to get out there and start going back to basics again.
"There is a case for not getting so uptight about things. Stiliyan wants to do really well and feels that Villa have not seen the best of him."
O'Neill added: "In his defence, Stiliyan has had to try and adjust to a completely new position.
"He never played this position at Celtic. We had a lot of the ball and he was able to go forward to get beyond the likes of Henrik Larsson, Chris Sutton and John Hartson.
"He could get goals because we had a lot of the ball. Here he is having to play much more of a sitting role even when he plays on the right hand side.
"I think all of these things are factors but, at the end of it all, he has the capability of playing better."