Pep Guardiola and Mauricio Pochettino will face each other in the Champions League semi-finals later this month, with the Argentine having met no manager more often in his coaching career than the former Barcelona boss.As players, the pair represented city rivals Barcelona and Espanyol, with both managing their respective clubs, so it's a rivalry that started on the pitch before continuing.After locking horns in Spain and the Premier League, they are now getting ready for a leaking collision in Europe's premier club…