Loris Karius’ motivation has been questioned after his latest error-strewn performance for Besiktas was heavily criticised by boss Senol Gunes.

The German goalkeeper joined from Liverpool on a two-year loan deal last summer and has struggled ever since his shocking display against Real Madrid in the Champions League final.

The 25-year-old was jeered by home supporters after he failed to make a routine stop to Omer Ali Sahiner’s equaliser on Sunday for Konyaspor.

And Gunes admits the goalkeeper is a problem for his team, saying he would prefer to use 35-year-old deputy Tolga Zengin if he were available.

“He was at fault for the goals he conceded,” Gunes said.

“Karius has gone a bit stagnant, something is wrong with his electricity, motivation, enthusiasm for the game.

“It has been like that since the beginning. He does not really feel a part of the team, it’s something we haven’t been able to work out and, of course, I am partly to blame for this.

“Something is wrong, he has also been unlucky. [He] is talented but it hasn’t worked out and we have a problem.

“Let me put it this way, if I still had Tolga available I would play him.”