By Iain Rogers BARCELONA, March 12 (Reuters) - It was hard not to feel sorry for AC Milan coach Massimiliano Allegri and his players after they were on the wrong end of a Barcelona backlash in the Champions League on Tuesday. Milan gave themselves a great opportunity to oust the pre-competition favourites after surprising them 2-0 in last month's last 16, first leg at the San Siro. However, Lionel Messi and his inspired team mates crushed the Italians 4-0 in the return game to progress to the last eight 4-2 on aggregate and keep alive their dream of a third European crown in five years. ... More...