The former forward also doesn't see Christian Benteke staying at the club past the summer.
The side looked destined for relegation after a dire season under Paul Lambert, but managed to avoid the drop with Tim Sherwood revitalising the side in an impressive second half of the season.
They also enjoyed an FA Cup run, beating Liverpool in the semi final only to be comprehensively out played in the final by Arsenal in a disappointing 4-0 defeat.
Yorke says there needs to be a big clear-out at Villa Park, with improvement desperately needed in the squad.
“Tim Sherwood needs a massive clear out over the summer and to improve the squad,” he said.
“Right now the mentality of the club has to be questioned. People will say avoiding relegation and reaching the cup final was a result but, in reality, it’s a huge wake up call. For the past few seasons they’ve narrowly avoided relegation.”
The former striker also believes that it is unlikely that star striker Christian Benteke will remain at the club past the summer.
The Belgian hit-man was a key player in the second half of the season, rediscovering his goal scoring form from the previous year after previously struggling following his injury.
His form has attracted the attention of a number of top clubs around Europa, with several Premier League sides in particular looking for a consistent and reliable forward, and Yorke believes losing him will be a massive blow to the side.
“I think it’s crucial Aston Villa manage to keep hold of Christian Benteke, but I also believe it’s highly unlikely they will,” he added.
“Losing him will be a massive blow. It will be hard to replace him and the impact he has on the side. His goals played a big part in Villa staying in the Premier League, after all.”