"He's good," coach Mike McCarthy said before Green Bay practiced Thursday. "That's what he keeps telling me."
Lacy was limited and his left ankle was heavily taped at Wednesday's practice.
If Lacy can start, he might also need to finish against the Cowboys.
Backup James Starks is nursing a knee issue that cropped up Tuesday, McCarthy said. Further complicating his situation, Starks left town and won't be back in Wisconsin until sometime Saturday because of a death in the family.
Starks is the only other running back on the 53-man roster behind Lacy as of Thursday's practice.
Undrafted rookie Don Jackson got all the work with the offense Wednesday and is a candidate to be active this week.
Lacy is off to a nice start this season with 295 rushing yards and an average of 5.5 yards per carry in four games.
Starks, in stark contrast, has gained only 42 yards on the ground and averaging only 1.8 yards per rush.
Although Starks has been productive on occasion during his six-plus years with the team, Lacy has been vital to Green Bay's offense in the early going this season. Lacy ran for 103 yards on just 17 carries in the team's pre-bye win over the Detroit Lions on Sept. 25, then had 81 yards on only 11 carries before he left the game against the Giants with the bum ankle late in the third quarter.
"When Eddie's playing at a high level like he was (last Sunday), it's definitely not only productive for our offense but it's the attitude and the finish that you certainly would want, and guys definitely respond," McCarthy said. "It gets your whole sideline going. It's definitely something we want to build off of."