"We are not going to lie," Walcott told reporters after Tuesday's game.
"We know as a unit it has been tough and we all had a good chat among us behind closed doors, without even any of the coaches or the manager knowing about anything and I think it is important that as a team we have got it in us."
The meeting, between Saturday's 2-2 premiership draw with Tottenham and Tuesday's 4-0 FA Cup fifth round win against Hull City, was led by seasoned players such as goalkeeper Petr Cech, defender Per Mertesacker and midfielder Tomas Rosicky.
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"I'd like to keep what was said among ourselves but it was very important," Walcott said.
Arsene Wenger's men will continue their bid for a first FA Cup hat-trick since Blackburn Rovers in the 1880s when they host Watford in the quarter-finals of the FA Cup on Sunday.
(Reporting by Shravanth Vijayakumar in Bengaluru)
