It has become apparent Xhaka is not capable as a single DM.
We bought him for his distribution but his positive contributions are negated by his limitations.
He has no athleticism so isn't quick enough to get into position or jump higher than his opponents. He is not well coordinated, seems wooden-legged, falls over at inopportune times and is too slow to get close enough to intercept or even commit necessary fouls.
At Moenchengladbach, he had a World Cup winning DM, Christoph Kramer, beside him so was able to express himself a lot more.
That is why i would not turn my nose up at Nzonzi who, unlike all the other players (Goretzka, for example) named, is available in January and he would free up several players (Xhaka, Ramsey, Wilshere, Ozil, etc) from primary defensive duties.