Chelsea captain Reece James tore into his own team after a dismal 2-1 defeat at home to Legia Warsaw on Thursday evening.

The Blues advanced to the Conference League semi-finals despite the shock setback thanks to a 3-0 victory in the first leg, but Enzo Maresca’s side were greeted by loud boos at the full-time whistle.

Maresca has been engaged in an ongoing battle to get the club’s fanbase onside, asking for “trust” before Thursday’s fixture. What faith supporters had in the Italian tactician was chipped away by the defeat to a side sitting fifth in the Polish top flight.

James also questioned some of his manager’s decisions. Maresca has embarked upon an odd rotation policy in recent weeks to avoid any further injuries to his star players and raised more eyebrows by taking Nicolas Jackson off at half-time, when the score was level at 1-1. Cole Palmer was removed shortly after Steve Kapuadi headed Legia into a 2-1 lead.

“We are making progress, [but] that was for sure not progress, if anything a step back,” James sighed. “Maybe we disrespected the competition today but this is football for you and if you don’t prepare right you’ll pay. Of course, it’s going to have an effect on the mindset going forward, it’s going to be in the back of people’s heads that we lost when we shouldn’t have.”

Maresca could only agree with his skipper. “For sure Reece is right,” he conceded. “More than the competition [Chelsea ‘disrespected’] the opposition.”

The Blues had ample chances in what James called a “poor performance” but were guilty of conceding very sloppy goals. Filip Jorgensen compounded his error in giving away a first-half penalty by limply letting Tomas Pekhart’s poor spot-kick squirm through his gloves.

Marc Cucurella hauled Chelsea level shortly after the half-hour mark and had a second goal correctly ruled out for offside – as did Tyrique George. Yet it was Legia who claimed a famous win as Kapuadi evaded James’ loose marking at a corner in the 53rd minute.

James couldn’t contest the boos at full time: “I understand the frustration to be honest, I understand fans come to games to see excitement to see goals. Today we were frustrating to watch but we remained focussed and we still stick together.”

Chelsea travel to Sweden to face Djurgardens in the first leg of their semi-final on Thursday 1 May before hosting the return fixture one week later. The winner will play one of Fiorentina or Real Betis in the final.