Boss Tony Mowbray has laid down the gauntlet to his Celtic squad to show their worth or risk being shown the door after their latest Europa League defeat.

Mowbray, who was appointed Gordon Strachan’s successor in the summer, gave the stark warning after Marcus Berg earned Hamburg a 1-0 win at Parkhead.

Celtic are rooted to the bottom of Group C and Mowbray insists he will make changes in January if he doesn’t see an improvement.

“It is now up to the players to prove they are worthy of staying at this club and playing in front of the fans,” said Mowbray.

“The fans will be happy with the endeavour, the effort, the commitment and the desire but I have never questioned any of that.

“But I can question their quality, as I did against Motherwell and as I do again. I saw our quality and their quality.

“Manchester United win games because Rooney smashes it in and Berbatov creates space and look at Liverpool – they are finding it hard without Gerrard and Torres.

“Quality is what counts – the best players win you football matches.”