O'Neill quit the Villa Park hot-seat on the eve of the season and neither caretaker manager Kevin McDonald nor the Northern Irishman's permanent successor Gerard Houllier have managed to achieve consistently good results with a highly-talented squad.
Villa do, at least, appear safe from relegation following last weekend's victory at West Ham but Pulis believes they should have done better. He said: "They are one of the great under-achievers this year.
"Martin O'Neill is one of the top managers in this country and for someone to take over from Martin was always going to be difficult. They are big shoes to fill.
"And with Gerard Houllier being out of the game for a while it was always going to be a slow transition and it has taken them a bit of time to get going.
"I am sure they will be better next year, they are a great football club. There are clubs that are at a level above us at the moment and Villa are one of them but we will try to go there and win."
Source: PA
Source: PA