Ally McCoist and Alan Brazil have suggested that Arsenal winger Gabriel Martinelli is running very hot and cold this season. After a stunning campaign last year where he helped the Gunners nearly win the Premier League, Gabriel Martinelli hasn’t hit the same heights this season. Speaking on TalkSPORT (10/1 6:16am), the pair were discussing Arsenal’s recent struggles. Back-to-back league defeats were followed up by a frustrating loss to Liverpool in the FA Cup. Mikel Arteta was without Gabriel Jesus due to injury and chose to play Kai Havertz as a centre-forward ahead of Eddie Nketiah. He start…