The South African-born Scot has been a revelation in recent weeks for The Owls but will be the first to admit that he started his Wednesday career slowly.
But vital goals in games against Preston and Brighton helped secure the club's status in the championship and he knows that the players all welcome the chance to enjoy the Derby game rather than fear it.
He told Footymad: "We go to Derby with no pressure on us so we can enjoy the occasion but we will go out this weekend and try to get three points and finish as high as we can in the table. You don't want to be going into the last game of the season needing something, I did that last year at Livingstone and the pressure was unbelievable but that day we managed to get the result we needed but here at Wednesday we have done the job with two games to spare and we are glad about it."
This season has been a mixture of lows and highs for the former Blackburn midfielder and it is something he is hoping to improve upon next year.
He added: "The first half of my season I think was disappointing and I wasn't in the team because of lack of form but in the second half of the campaign I managed to get a good run of games under my belt and my form has picked up but the main thing at the end of the day is knowing you are staying in the league. I scored two crucial goals as it turned out but I have said it before, two goals so far in a season is really disappointing and I am going to try to improve upon that next year."
Planning for the future though is first and foremost for O'Brien who has got some very important plans for the summer months.
"I'm actually getting married next month so I just have to finalise things in the next few days that's my plan for the summer," he beamed. "We have been to Dubai the last two years and we enjoyed it so we are going back there for the honeymoon."