City have suffered a slow start to their European campaign, having fallen to defeat at the hands of Real Madrid before scraping a home draw against Borussia Dortmund.
However, the club captain has called on his team-mates to move on from earlier disappointments and show belief they can win every game.
"The past is irrelevant; we’ll go into tomorrow’s game hoping we can win like we always do," he told reporters.
"It’s wrong to bring up everything that might have gone wrong in the past, i think we have shown so many great things in the past couple of years.
"We have done a lot of great things this season. When it comes to character, when it comes to spirit and strength within the team to overturn situations, that’s something we can only achieve collectively.
"We still think we have got a big chance and we are capable of winning every game. We will go into the game tomorrow with a positive attitude and with the feeling we have had a good start to the season.
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|8/1||Manchester City are 8/1 with bet365 to win Group D
City face Ajax on Wednesday with Frank de Boer’s men sitting bottom of Group D and yet to earn a point, but Kompany is certain his side will be tested at the Amsterdam ArenA.
"Ajax is a club of legends and has always had one of the best youth systems in the world," he continued.
"I have a massive amount of respect for Ajax. Obviously tomorrow is a game we need to win as much as they need to win.
He added, "I think it’s a very tough group. There’s not gonna be any easy games, tomorrow is gonna be [difficult] one again. It’s very tight, but that makes it exciting.
"We’re a very disciplined team and we have shown we have a great capacity to react, and tomorrow is a different game, a different set-up and it’s just important to win."