Boss Garry Monk said he felt he may have made errors in his FA Cup team selection and admitted Sutton United deserved their victory.
The Whites boss now wants his players to immediately turn their attentions back to pushing for promotion to the Premier League.
“I take responsibility for this performance,” he said. “I’m the one that selected the team, I’m the one that made a lot of changes, it didn’t work out for us. So maybe it was the wrong decision in that sense.
“Our performance didn’t warrant the result so credit to Sutton, good luck to them in the next round. But like I said, I take responsibility for that, maybe it was one or two too many changes. There was no cohesiveness to our play so we got what we probably deserved.
“The bigger picture for us is we have to move on, we’ve got a game in a couple of days (away at Blackburn). We have to refocus straight away and make sure that we’re ready for the next game.”