Roberto De Zerbi: Unai Emery one of the best coaches in the Premier League

Fourth-placed Villa travel to the Amex Stadium on Sunday afternoon to resume their pursuit of Champions League qualification in the middle of a two-legged Europa Conference League semi-final against Olympiacos.

Villa were outside the relegation zone only on goals scored when Steven Gerrard was sacked 11 games into last season.

Former Sevilla, Paris St Germain and Arsenal boss Emery subsequently guided the West Midlands club to a seventh-placed finish and is destined to hit greater heights this term.

Asked about the Spaniard's performance, De Zerbi, whose side were thrashed 6-1 at Villa Park in September, told a press conference: "Incredible.

"I think he's another big coach, another one of the best coaches in the Premier League.

"His experience is amazing, his style is clear.

"They have very important players, they spent a lot of money in the last transfer market session.

"They deserve to fight to reach the Champions League, they have very good players and they have a top coach."

Villa have work to do to reach the final of Europe's third tier tournament after suffering a 4-2 home defeat to Olympiacos on Thursday ahead of next week's second leg in Athens.

Yet Emery's men look almost certain to be playing in the continent's leading club competition next season as they sit seven points clear of fifth-placed Tottenham, albeit having played a game more, with just three fixtures remaining.

In contrast, Brighton's quest to secure another European campaign is effectively over following a costly run of six games without success.

De Zerbi admits his side's faltering Europa League push, amid a string of injury absentees, caused a decline in energy and motivation.

"I spoke about motivation not because we would like to go on holiday tomorrow or last week but because when the target is not so close it's tough to accept for a team used to fighting to reach the important target," said the Italian.

"This season until the Brentford game (a 0-0 draw on April 3), until maybe the Burnley game (a 1-1 draw on April 13) we had the chance to qualify for another year in Europa League.

"After those games, I think we lost something of energy, something of motivation.

"But I think it's a normal part of the way."