"Father Time is undefeated, man," Billups said.
Asked if that means he could lose the inevitable fight, Billups didn't bother playing it coy.
"My gas light is on," he said.
"It all kind of depends how this feels and how things are with the knee," he said. "If the knee is fine, then sure, absolutely, I would like to come back. If it's not, I don't want to come back and do this. It's tough to do this, especially on a team when we're not a winning team at this stage."
The Pistons are 23-34, and Billups said he thought that they'd be higher up in the standings if he had been healthy all season. The 37-year-old has suited up in just 19 games for Detroit this year, averaging 3.8 points and 2.2 assists in 16.3 minutes per game. His last appearance was a nine-minute stint against the Brooklyn Nets on Feb. 7, and before that it was seven minutes against the Philadelphia 76ers on Jan. 10.
Billups signed with the Pistons in July and said at the time he thought he had some good years left. The contract was for two years and $5 million, but Detroit has a team option on the second season.