The Welsh side's difficult season took another turn for the worse on Saturday as Ben Watson's piledriver handed Wigan a place in the quarter-finals of the competition they won last year.
Cardiff currently sit second from bottom in the Premier League table, with only 12 games left to play.
Solskjaer - who took over from the sacked Malky Mackay in January - has picked up just four points from a possible 18 since taking over the helm.
But he was keen to look forward after the 2-1 cup exit, and insists that he is simply focused on keeping Cardiff up.
"We are out of the cup now so there is only one thing we have to concentrate on and that is the league," he said.
"I'm made in a way that I always try to see something positive, even in a defeat like this if you can. Today is not easy as we thought we had a chance to go all the way. The league and survival in the top flight is now what we have to concentrate on."
Cardiff had their chances to extend their cup progress, with Wilfried Zaha particularly lively after Chris McCann's 17th-minute opener had been cancelled out by Fraizer Campbell.
But Watson's strike was simply unstoppable, after the ball was touched to him from a free-kick, and the former Manchester United striker conceded that his team had been masters of their own downfall.
"We are out of the cup so there is nothing more to say, we are disappointed," Solskjaer added.
"We thought we were in with a chance here today and we were as we created chances, but we didn't take them.
"But we conceded a poor first goal - it was a stupid foul to give away as we should have got it away.
"With the second goal, there was nothing we could do because it was a wonder strike.
"We play the percentages and it might go for us but it didn't today. I can't fault the effort - it was a top spirit given by everybody.
"It was just one of these days and we just rue the missed opportunities."
