Ba hobbled out of the Magpies' 2-1 victory over West Bromwich Albion at the weekend after picking up a knock.
He has been undergoing treatment since, in an effort to get him ready for a crucial clash at Anfield, but faces a race against time to prove his fitness.
Newcastle boss Alan Pardew concedes that he may make the journey to Merseyside without his leading goalscorer, but believes his squad has the strength in depth to cope with such an absence.
"I think he's 50-50, at best," Pardew told the Evening Chronicle on Ba's chances of lining up against Liverpool.
"We've got Papiss (Cisse) back on the goal trail and Shola and Sammy (Ameobi) so we're happy with that.
"It is very important to have that.
"Papiss is fit and well and we are looking forward to seeing him this weekend."