Enzo Maresca's naive tactics were exposed and his side made too many mistakes playing out the back - but there was ONE positive for Chelsea: FIVE THINGS we learned after the Blues' humiliating 4-1 defeat by Celtic
KIERAN GILL IN NOTRE DAME: The number of times that Celtic beat Chelsea's high line with a single ball in behind was concerning, made worse by the lack of press from Enzo Maresca's players.