A round-up of the latest Arsenal news as FC Porto boss Sergio Conceicao fires a dig at Mikel Arteta and the Gunners lead the transfer race to sign an in-demand wonderkid. Bukayo Saka and Gabriel Martinelli were ‘not as effective’ as Arsenal lost at PortoPorto hold a 1-0 advantage over Arsenal after the first leg of their Champions League last 16 tie. And Gunners hero Theo Walcott feels Gabriel Martinelli and Bukayo Saka were both ‘not as effective’ as expected during their meeting at the Estadio do Dragao on Wednesday night. Galeno secured the Dragoes the aggregate advantage in the 94th minute…