PEP GUARDIOLA promised to call his successor as he prepares to hand over the managerial reins at Manchester City.Guardiola took charge of City for the final time as their Premier League campaign ended with a 2-1 defeat to Aston Villa at the City of Manchester Stadium on Sunday.The Spaniard leaves after 10 glorious years in which he won 20 trophies, including six Premier League titles and the Champions League. His last season saw him deliver a domestic cup double and a runners-up league finish.