In an interview with Arsenal's official website, Merino discussed his position on the pitch.
Do you prefer playing forward or midfielder?
That depends on which center-backs you're facing! If they're very strong, midfield might be better! But I'm happy and comfortable in both positions. I have a good ability: I understand what's required in different positions, I can adapt to the coach's demands, adapt to the team's needs, and feel comfortable in both.