By James Cormack A quarter-final place is at stake when Barcelona host Napoli in the second leg of their Champions League round of 16 tie on Tuesday night. Barca have drifted into utter functionality in recent weeks, but they’ve continuously found ways of getting the job done without particularly impressing since Xavi revealed that he’ll be stepping down at the end of the season. The La Liga outfit still have a whole host of injuries, with their woes on this front worsening since their 1-1 draw in Naples three weeks ago. Here’s how Barcelona could line up against Napoli for their decisive seco…