Mikel Arteta has now sent a clear message to Arsenal supporters ahead of Tuesday night’s clash with Porto. Mikel Arteta has made it plain what he expects from Arsenal fans when Porto come to the Emirates Stadium. The Gunners will contest the second-leg of their Champions League round of 16 knockout clash against the Portuguese outfit on Tuesday evening. The visitors come into this match with an advantage, after they snatched a late victory at the Estadio do Dragao in the first-leg. With Porto holding a 1-0 aggregate advantage, there is no room for error for Arsenal in this match. Whilst the no…