Journalist Sam Dean was seriously impressed by one Arsenal player in the second half of their clash with Porto on Tuesday evening.Jakub Kiwior produced a defensive masterclass for Arsenal against Porto on Tuesday evening. The Polish defender has been in impressive form in recent weeks whilst playing a left-back for the Gunners. Despite being a centre-back by trade, the former Spezia man was initially called upon to fill-in on the flank of the rearguard following injuries sustained by Oleksandr Zinchenko and Takehiro Tomiyasu. In the past, when Mikel Arteta has called upon Kiwior to do a job fo…