Petr Cech hailed Arsenal's squad strength after their FA Community Shield shootout victory over Chelsea at Wembley.
Gunners new boy Sead Kolasinac cancelled out Victor Moses' earlier effort as the game finished 1-1 after 90 minutes, before Arsenal won the penalty shootout 4-1 under the new ABBA system.
Kolasinac had come on as a first-half substitute for the injured Per Mertesacker, while Arsenal were without the likes of Alexis Sanchez, Mesut Ozil, Aaron Ramsey and Laurent Koscielny.
"We were missing a lot of players but it's great to see that everybody is ready to compete for places in the squad for every game,'' Cech told BT Sport 1.
"Sead came in when Per got injured. He had a great game and everyone who came in as a sub helped us keep our quality on the pitch.
"The most pleasing thing for us is that we showed that we are ready to compete.''
Arsenal's record signing Alexandre Lacazette struck a post in the first half before Moses -- red-carded when Chelsea lost the FA Cup final to Arsenal in May -- equalised within seconds of the re-start.
But Kolasinac headed Arsenal level eight minutes from time, just moments after Chelsea forward Pedro had been shown a straight red card for a tackle on Mohamed Elneny.
"You could see there was small margin between both teams in the 90 minutes,'' Cech said.
"But we have got to be pleased with our performance because we did really well and got punished for one bounce in the penalty box.
"We showed great composure to come back to the game and then it's penalties and who keeps their cool better.''