Having joined late in the summer transfer window from Real Sociedad, Merino is still getting used to the differences in training methods with the Gunners which he says is unbelievable when compared to Spain.
“Very intense, much different (to Spain)," he said of the training under Arteta, speaking to the club's media team in a 'Colney Carpool' segment. "I don't think it's always different to Spain but I think it's different to everywhere else. The methodology they have here is unbelievable."
"Not only on the pitch but also in the gym. I don't know. The hard work that they put in always, every member of the staff is always on top of us, making sure we have what we need to improve. Unbelievable."
Arteta’s training sessions are clearly paying off as his Arsenal side are still unbeaten so far this season in all competitions despite numerous injuries including Merino.
The Gunners face Bournemouth this weekend as they travel to the Vitality Stadium after a well-deserved international break.