By Grey Whitebloom Real Madrid welcome Barcelona to the Santiago Bernabeu in La Liga on Sunday afternoon. The last time Madrid hosted their fierce Catalan rivals Carlo Ancelotti had a tactical headache in the absence of Karim Benzema. Without a recognised number nine, there were plenty of options for the Italian – who did his best to try them all. Starting with Luka Modric as the furthest forward player, Ancelotti switched to a back-three with Madrid trailing 2-0 at half-time. Only four minutes separated Barcelona’s third and fourth of the night but that was still enough time for a return to a…