With just days remaining of the summer transfer window, Mikel Arteta is searching for the last piece of the puzzle for Arsenal in their pursuit to win the Premier League. Arsenal could have Mikel Merino available to face Brighton & Hove Albion this weekend, another excellent signing for the club. Merino would join David Raya and Riccardo Calafiori as the club’s three permanent arrivals this summer, a stellar trio. That being said, Arsenal are unlikely to stop there, and could still sign as many as two or three more players. Arsenal are pushing to sign Joan Garcia right now, a move that will de…