What did he actually do last season besides fail miserably?
He helped Leicester to QF of champions league and scored 10 goals across the season.
Was sulking at times but still on his day a very good player.
If Barca wanted him for 80/90m and a starter wouldn't be happy but if can get for 40/50m and help depth on bench would take it. As long as it is not st expense of midfield.
When Barca use likes of Deulofeu and Paco as back up in wide areas or use Vidal that is not good enough. Mahrez is far better player than those three.
Don't think he will come anyway but he would help with depth and upgrade options in my opinion.