By Mandeep Sanghera

Mellberg says Villa need consistency Preview: Portsmouth v Villa Lawro's Premiership predictions

Olof Mellberg has warned some of Aston Villa's players to prepare themselves for disappointment when David O'Leary picks his first side for a competitive game on Saturday.

O'Leary took over at Villa after Graham Taylor quit in May and will be in charge for his first Premiership match when the Midlands outfit visit top-flight newcomers Portsmouth.

Mellberg says the current positive vibe at the club will be upset when certain players find they have not impressed O'Leary enough to earn a place in the first team.

Last season, striker Juan Pablo Angel and defender Alpay had to watch from the sidelines under Taylor.

"The atmosphere is good at the moment," said 25-year-old Sweden international Mellberg.

"A new manager has come in so everyone feels like they are starting from scratch again, especially those players who felt like they did not have the confidence of the last manager.

We want to be at the top half of table and if we can start well and be up there we can always look up as the season goes on Olof Mellberg

"They feel it is a fresh start and everyone is working hard and fighting hard for a first-team place.

"But people are going to get disappointed when they feel they do not have the confidence of this manager."

He added: "It's very difficult to avoid that situation.

"We all want to play and some will get their chances and some will not. We will just have to see if Alfie and Angel get theirs."

Mellberg helped Villa to the top of the table under former boss John Gregory but has also sampled the bad times since then as the side's fortunes have declined.

He is acutely aware that whatever team O'Leary fields, a run of good results will be the vital factor in helping keep a positive mood around the club and re-establish Villa as a top-flight force.

"You just need to get the results and everything else will solve itself," he said.

"We want to be at the top half of table and if we can start well and be up there we can always look up as the season goes on."