The 39-year-old Timonen, who signed a one-year contract last summer for $2 million, skated with the team Thursday and has said he'd be willing to play against the New York Rangers on Saturday night.
"If they want me to play Saturday, I'm good to go," Timonen told reporters Thursday. "Every day is better, and I have to start playing games somewhere down the road. If it's Saturday, that's good. If it's not Saturday, then it's next week."
After doctors found the blood clots, Timonen said in September that the chance of him playing this season was "really slim." He also has said he will retire after this season.
"It's a huge, huge step for me," Timonen said of being able to return.
Timonen has been Philadelphia's top defenseman for several years and has spent the last seven seasons with the Flyers after playing his first eight with Nashville. He has 571 career points on 117 goals and 454 assists. Timonen is plus-38 for his career.
The Associated Press contributed to this report.