Arsenal completed the signing of Mikel Merino this week but Mikel Arteta may yet have one more signing in mind before the transfer deadline. The Gunners had already tied up two important signings before the Premier League season kicked off. David Raya’s loan became permanent and Arsenal invested in defender Riccardo Calafiori having been impressed with him at Bologna. Arsenal have now bought Mikel Merino, luring him away from Real Sociedad to bolster Mikel Arteta’s engine room. A departure now seems to be the next move with Eddie Nketiah on the verge of joining Crystal Palace. That may just pa…