Antonio Conte believes Chelsea passed up “a great chance” to win the FA Cup last season and will find success this year far harder to come by as they prepare for Sunday’s semi‑final against Southampton.

The Italian, who has yet to claim a knockout trophy as a manager, had seen his team secure the Premier League title by seven points last term, finishing 18 clear of Arsenal, their opponents in the cup final. Yet Chelsea failed to maintain the high standards they had set – they won 19 of their last 23 fixtures in all competitions before the showpiece – and his 10 men succumbed to a late Aaron Ramsey goal to lose 2-1.

Conte was speaking before knowing that Manchester United, rather than Spurs, would await in the final if Southampton, struggling badly in the top flight, were overcome. “I must be honest: last season, we missed a great chance to win the FA Cup,” said Conte. “This season, if we can win against Southampton and reach the final, it would be more difficult against Tottenham or United. Last season we were in the best condition to try to go and win the FA Cup, and we missed that chance. It was our fault.

“I remember that some refereeing decisions were not good. The first goal scored by [Alexis] Sánchez was handball, and we finished the game with 10 men [after Victor Moses’ dismissal for two bookings]. But, despite this, we were able to equalise only to concede a goal at the last with our mistake. Arsenal did a great job to win the FA Cup but we could have done better. At that moment we were stronger than them. This season, it would be more difficult to win it.”

Conte, who is expected to leave Stamford Bridge in the summer, will not be appeased for a difficult campaign by a second successive appearance in the FA Cup final. “You have to know that I play only to win,” he said. “I don’t play to enjoy. I play only to win. Every season I start the season with only one idea in my mind, in my heart, in my soul: to win.

“If I win something, I did my job, not something special. If we don’t win, I’m very angry, above all with myself. But I’m ready to work harder to try and win something the next chance I have.”

Southampton were overcome in a league meeting between the sides last Saturday despite Chelsea trailing 2-0 at St Mary’s with 20 minutes remaining. Olivier Giroud, who should start at Wembley, transformed that occasion following his introduction from the bench, and Conte hopes his players have learned lessons from the contest on the south coast.

“If we are the team that played the first half and a part of the second half, we must be concerned, really concerned,” added Chelsea’s head coach. “But if we go to play with the right team spirit, we have a possibility of reaching the final. My players have to go on to the pitch with the right fire in their eyes, with the right desire to reach the final, and with our crowd with us. We must give them the best satisfaction.”