But the young City midfielder has tried to put the episode behind him and this week signed a new five-year deal with the Blues.
Sven has been impressed by his response and believes he could be ready for a recall after missing last week's 1-0 win over Aston Villa, when Darius Vassell came in on the right of midfield for his first appearance of the season.
"I'm very happy he's signed," Sven said about Ireland's new deal.
"He's a very, very good footballer and one coming from the Academy, so that's one more we have for the long term.
"I think that he will play a very good football match for us on Saturday, he's training very well."
Dunney is back from a one-match ban for his red card at Blackburn and should return to the middle of defence, with Vedran Corluka going back across to right-back and Nedum Onuoha dropping back to the bench.
I also hope Sven brings back Rolando Bianchi in place of Emile Mpenza up front as Bianchi seemed to show more hunger and threat as a late sub against Villa than Mpenza did in the rest of the match.
Sven will also be hoping for another big contribution from Michael Johnson, last week's match-winner against Villa.
"He's a very good all-round football player," Sven added on the City website. "He can do everything on a football pitch, and of course he's young and will get better and better. It's great for the club to have young players like that.
"He wants to play football, he loves to play football and he trains very hard every day at Carrington. We need that from him, and the goals he's scored so far for us this season have been very, very important."