The Congolese striker was stretchered off in the opening minute of last week's clash with Bristol Rovers following a crunching challenge from Steve Elliott.
Initial fears that Zola had broken his leg were played down by manager Steve Holland, but the 23-year-old is still rated extremely doubtful due to a large gash on his lower shin.
Defenders Chris McCready and George Abbey are both ruled out with hamstring injuries, but Holland can call on the services of giant centre-back Dennis Lawrence, who completed a loan move from Championship side Swansea earlier in the week.
Midfielder Ben Rix remains on the sidelines with suspected ligament damage in his foot.
Northampton captain Chris Doig is expected to return as the Cobblers seek their first league win since the opening day of the season.
Doig has missed the last three games with a groin injury but came through 90 minutes of the midweek reserve draw with Ipswich unscathed and is in contention to start at Gresty Road.
However manager Stuart Gray has a tactical dilemma on his hands after full-back Jason Crowe's two excellent performances as a makeshift centre-back.
Striker Adebayo Akinfenwa grabbed a brace in last weekend's 2-2 draw with Brighton and will again partner Karl Hawley in attack as Gray has a fully-fit squad available for the first time this season.
On-loan Blackburn goalkeeper Frank Fielding will keep his place in goal while last season's player of the year Danny Jackman will hope to return to the side.
Sporting Life