The full-back says the Blancos skipper retains his full support but argues that every player must accept that there is always a chance of being dropped
After a very public falling-out with former Blancos boss Jose Mourinho, Casillas had been expected to reclaim his starting berth this season under new coach Ancelotti, but the Italian has gone with Lopez for the opening two rounds of the Liga campaign, including Monday's win over Granada.
That has caused uproar at the Santiago Bernabeu, where Casillas remains an icon, but Arbeloa would like to see an end to the unrest.
"The season is very long," the Blancos full-back told reporters after Monday night's game against Granada. "It's 11 months, so there's plenty of time for everyone to help out.
"Iker is our captain and he has a lot of experience but he should be an equal. I understand and support Iker, but we are professionals.
"Whoever plays will have our support, and the fans should do the same. The debate is out there but it is the reporters who are more interested in it. We're calm.
"We must respect the coach's decisions. We have to focus on the team. We already have too many enemies without trying to kill each other!"
Madrid made it two wins from two in la Liga with a 1-0 win over Granada, with Karim Benzema scoring the only goal of the game.