Cahill was in action for Palace in their Premier League game against Chelsea away from home at Stamford Bridge in London on Saturday.
The 33-year-old central defender was on the books of the Blues from 2012 until 2019, and played an important role in the London club winning the Premier League title twice, the FA Cup twice, the Champions League once, and the Europa League twice during that period.
The Englishman parted company with Chelsea at the end of last season and joined London rivals Palace on a free transfer in the summer of 2019.
Chelsea legend Cech, who now works as a Technical and Performance Advisor at the club, was pleased to see the Stamford Bridge faithful welcome Cahill back in style.
Chelsea won the game 2-0 against Palace, thanks to goals from Tammy Abraham and Christian Pulisic in the second half.
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