Arsenal are third in the Premier League table, eight points behind Leicester City, and are facing a Champions League last-16 exit for the sixth year in a row unless they can overturn a 2-0 first-leg deficit when they travel to Barcelona next week.
"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.
Arsenal manager Arsene Wenger and assistant Steve Bould
Image credit: Reuters
"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.
Have crisis talks paid off?
It looks like Arsenal have realised there is a strong requirement to raise their performance levels. They were unfortunate not to win with 10 men against Tottenham on Saturday while they ruthlessly swatted aside Hull in their FA Cup replay on Tuesday. It was much more like it from Arsenal after they turned in a couple of abject performances in losing at Manchester United and Swansea in the Premier League, defeats that may yet damage their hopes of claiming a first national title since 2004.
Clearing the air talks is not really the issue here, you wonder why they were needed in the first place? When you witnessed Arsenal against Spurs and Hull in comparison to the defeat at United, you do wonder how they are capable of turning in performances of such poverty when their squad is rich in flair. Arsenal obviously need to find some measure of consistency if they are to breathe new life into a Premier League campaign that is faltering. It is debatable if crisis talks will help to solve such a problem, but it is worth a go.