Speaking to reporters after the match, the Gunners boss said: "He [Saliba] twisted his ankle during the warm-up. He came in and he said he believed that he could carry on and play but straightaway in the first two actions I could see that he couldn't cope and we had to get him out, unfortunately. But thank God we have Mosquera, which we put in for the first time in the Premier League, his debut, not expecting it at Anfield and I think he was really, really good."