The 20-year-old Serb, who collapsed after trying to turn just behind the baseline and was in tears before winning a further three points to complete the match, is now also doubtful for the Dubai Open which starts on Monday.
"The injury is not as bad as I thought," Ivanovic said on Thursday after returning from hospital in Doha.
"It's a disappointing way to end the tournament and I thought I was in good shape."
Ana Ivanovic |
"There is no fracture. It is an ankle sprain. But it is pretty painful and it is hard to step on it. It's a disappointing way to end the tournament and I thought I was in good shape.
"But it is a fine line between it being a small and a serious injury, so I just have to take it day by day."
Second seed Kuznetsova, Qatar Open runner-up in 2004 and 2007, was sensationally beaten in straight sets by Austrian 15th seed Sybille Bammer, 6-3, 7-6 in difficult conditions on centre court at the Khalifa International Tennis complex.
Extreme conditions
The Russian made more than 50 unforced errors in a match played in strong, swirling winds, with Bammer finally prevailing on her fourth match-point opportunity to win the second-set tie-break 10-8.
"I fought, but I did not really start fighting till the end," Kuznetsova admitted after the match.
The world number two even suggested matches should be postponed due to extreme winds.
"It was in my head two or three times someone should cancel this because it's a disaster. I couldn't play the ball. It was embarrassing to stay out there.
"It was very disappointing to lose like that to her. I could not play my game."
Williams wipes out
The 27-year-old Bammer, who recorded her first win over Kuznetsova in five meetings, will play another Russian in the quarter-finals in the form of Vera Zvonareva, who defeated 11th seeded compatriot Dinara Safina 7-5, 6-3 as the seeds continued to tumble.
In yet another upset, Slovakia's Cibulkova ousted sixth-seeded Williams in straight sets, 6-3, 6-3 with the American making a staggering 40 unforced errors to her 18-year-old opponent's four.
Cibulkova, who is ranked 45 in the world to Williams' seven, will take on 16th seed Agnieszka Radwanska in the quarter-finals after the Polish player advanced via walkover due to Ivanovic's withdrawal.
On court one, Denmark's Caroline Wozniacki overcame Spain's Anabel Medina Garrigues 3-6, 7-6, 6-3 to set up a quarter-final against the winner of the match between 2005 champion Maria Sharapova and Thailand's Tamarine Tanasugarn.