The 33-year-old has been struggling with injury and has not played for the first team since March of last year.
The Welsh international is still some way short of reaching the level of fitness required to play in the Premier League but has recently returned to training.
Manager Martin Jol told Clubcall: "Simon is almost a project.
"We tried to get him fit but decided not to play him in the development game against Crystal Palace last week.
"He wanted to play 45 minutes but I thought it was better for him to start this week.
"He's training with us now and we're monitoring him closely. Last year he had to play in the reserves to get fit and then he was out again with another injury.
"He feels a bit better but is still three or four weeks away from being ready for the first team."
The former Tottenham and Everton player will be out of contract at Craven Cottage in the summer.