Spiller remains on injured reserve with a designation to return. The team has until Dec. 24 (21 days after he returned to practice) to add him to their 53-man roster, but they must make that move by 4 p.m. ET Saturday for him to be eligible to play in Sunday's game against the Oakland Raiders.
The Bills listed Spiller as a limited participant in Wednesday's practice, the beginning of his third week of practice since returning from a broken collarbone.
"I'm not gonna sit up here and say he didn't look good," coach Doug Marrone said after Wednesday's practice. "He looked good, but he's still working his way back into the football part of it."
Spiller last played in a win Oct. 19 over the Minnesota Vikings.
"I feel good," Spiller said Wednesday. "We'll see how the rest of the week goes, to be honest."
The Bills have yet to make a decision on whether Spiller will play Sunday in Oakland. If the Bills' want to keep their slim playoff hopes alive, it's a game they must win.
"Obviously that does play a big factor," he said, "but at the same time, be smart about it."