Fortune sees Premiership future for West Brom
Fortune was on loan with the Baggies when they slipped out of the Premier League in 2008/9, and he left at the end of the campaign to link up again with Tony Mowbray at Celtic.
Although West Brom have made a habit of going up and down between the top two divisions in recent years, the 29 year old is confident the club can stay up this term.
"We know the mistakes we made," he said.
"We have new players now and we're ready. It will be difficult but if we don't give up we'll be okay."
Fortune says one of the main reasons for his confidence is manager Roberto Di Matteo and his tougher training regime.
"The gaffer has a different way of managing the team (to Mowbray)," he explained.
"I've only been here for one week but I can see that the way we train and the way the manager wants to play is different.
"We have to be at 100% every training session. If we train hard like that we can be ready for every game.
"We also know that we have to be good defensively. We made mistakes in the past that we have to avoid now."