Aston Villa boss Unai Emery says it will not be a failure if his side do not win the Europa League . Villa were pre-season favourites to win the competition, with Emery chasing a fifth title, but they are up against it in their all- English semi-final against Nottingham Forest , trailing 1-0 from last week’s first leg. With a summer of change on the cards at Villa Park, there is a perception that this is the end of the cycle for a Villa side that reached a Europa Conference League semi-final and Champions League quarter-final under Emery. The Spaniard, whose side have lost their last three games, says there is more for his squad to give and denies Thursday’s clash with Forest will define the season. “We are usually getting higher level with the club, with the players. We are improving – myself as well,” he told a press conference. “We will have after tomorrow our way to set more challenges for the present or future. I don’t think tomorrow is the last opportunity for us or for anyone.…