The duo could be given their chance after the injury to Per Mertesacker.
The German defender is expected to miss five months of the season after picking up a knee injury sustained in pre-season training.
That has left the side desperately short of numbers in the centre of defence, with Laurent Koscielny also absent as he takes an extended rest following his exertions with France at Euro 2016.
Arsenal's Per Mertesacker comes off injured
Indeed, manager Arsene Wenger has already stated that he will be forced into buying a new defender to cover the loss of Mertesacker.
But Cech has called upon new signing Rob Holding, and forgotten man Calum Chambers to seize their chance.
“We will need to make sure that the players who will get their chances to play more, they will take it and they will rise to the occasion,” he told ESPN.
“It's up to (Holding) how he's going to play and how he's going to work. The same is true for Gabriel and Calum Chambers. This is their moment to show the manager they are up to the task.”
Bolton Wanderers Rob Holding and Leeds United's Mirco Antenucci
It remains to be seen if either Holding or Chambers can take their chance in Mertesacker’s absence.
The latter will be particularly keen to impress given the manner in which he has fallen down the pecking order over the last year.
Mertesacker’s injury could be the break he has been waiting for though, and he will be determined to convince Arsene Wenger that he is the man he should turn to.
Arsenal's Calum Chambers in action with Hull's David Meyler