The Bhoys boss was speaking to reporters after a 3-2 win over Malmo.
Indeed, many Celtic fans were bitterly disappointed that the Bhoys conceded two goals despite scoring three at home against the Swedish side.
And Deila conceded that his team were also 'very irritated' with the manner of the goals they let in.
But the Celtic boss is remaining positive. When he spoke to reporters after the game - which is still a Champions League win at the end of the day - he said the fact Malmo have to attack Celtic in the second leg will suit the Hoops.
RD: We can win. We can beat Malmo but they have to attack us so that could suit us.— Celtic Football Club (@celticfc) August 19, 2015
Meanwhile, the Norwegian also highlighted the fact that Celtic carried the same margin into their second leg against Qarabag in the qualifiers.
On that occasion, the Bhoys traveled to Azerbaijan and did what they had to do: keep a clean sheet.
RD: We are ahead by one goal and we were the same against Qarabag and we defended there. We can do that.— Celtic Football Club (@celticfc) August 19, 2015
If Malmo win 1-0, they will have knocked Celtic out on away goals. But a Celtic win or draw will be enough after their 3-2 victory on Wednesday night.
Naturally, without the two goals Deila's men let in, things would be much easier. That, however, is football.