Coach Mike Smith listed Ryan as "limited" after a two-hour session Thursday.
"I'm feeling pretty good. I'm getting a little better every day, which is a good thing," Ryan said. "I'm just doing everything that I can at this point to get it back to where I can go back out there and play well."
A toe injury has prevented Ryan from participating fully in practice since the week of a 20-17 win over Tampa Bay. He missed two games, home losses to Philadelphia and New Orleans, before returning last week to help the Falcons take a road victory last week against the New York Jets.
Considering Ryan has just one loss in 13 career starts at the Georgia Dome, Atlanta needs him to help salvage the team from continuing a 44-year franchise history with no consecutive winning records.
After facing the Bills (5-9), the Falcons (7-7) end the season next week at Tampa Bay.
Ryan proved to Smith last week in pregame warmups at Giants Stadium that his turf toe injury had healed enough to let him effectively plant his feet and make accurate throws.
After enduring a difficult three quarters, Ryan showed why he was last year's NFL offensive rookie of the year. He began making accurate reads against the blitzing Jets and completed four of six third-down passes in the fourth quarter.
On fourth-and-goal and 1:13 remaining, Ryan and tight end Tony Gonzalez connected on a tight inside route and a 6-yard winning touchdown.
Ryan, the No. 3 overall draft pick of 2008, started every game last year and the first 12 this season before leaving in the first quarter against Tampa Bay.
"I was a little bit sore on Monday, but not bad," Ryan said. "I felt good, feel good today, and hopefully can get out and knock some of that rust off again when we get out working in the walk through and practicing."
Ryan's close friend, receiver Brian Finneran, believes the quarterback will maintain the high capacity he showed late against the Jets.
"As much as they stopped us throughout most of the game, a few good plays in recognizing blitzes and hitting Jerious (Norwood) in the flat on two good hot reads, little things like that come up big," Finneran said. "He's a good football player and a good competitor, but again it gets back to studying and understanding defenses. The desire is there."
NOTES: Finneran, whose season ended two weeks ago with torn knee ligament, said he plans to visit renowned orthopedist James Andrews next month and get a diagnosis that could determine whether the 11th-year veteran returns in 2010. Finneran missed all of 2006-07 after undergoing two reconstructive surgeries on his right knee. ... RCB Chris Houston (hamstring) and Pro Bowl RB Michael Turner (ankle) did not practice Thursday. ... Listed as limited in participation were two other offensive starters, LT Sam Baker (elbow, hamstring) and RG Harvey Dahl (ankle), and three other defensive starters, DE Jamaal Anderson (chest), DT Jonathan Babineaux (shoulder), LB Curtis Lofton (shoulder, hamstring).