Journalist Simon Collings has now identified one Arsenal star who looks to be losing form and has sent a warning to Mikel Arteta. The Arsenal defence had a rare off-day against Aston Villa on Sunday. The Gunners were beaten 2-0 by the Midlands outfit at the Emirates Stadium, as a quick-fire double late on in the game secured a win for Unai Emery’s men. This result was a significant blow for Arsenal’s Premier League title hopes. The North London club have now surrendered control of the title race to Manchester City. Mikel Arteta will believe that his side can still win the league, but they will…