Jankovic struggled with her arm throughout Roland Garros
Defending champion Jelena Jankovic has joined Maria Sharapova on the list of withdrawals from the DFS Classic.
The Serbian will not play in Birmingham because of an arm injury sustained at the French Open.
Sharapova, who has a shoulder problem, said: "I've got to make some mature decisions that will help my career."
French Open runner-up Dinara Safina has also pulled out with a lower-back injury in another blow for Birmingham, which is battling to retain the event.
Sharapova, who has won the tournament twice and played there for the last five years, hopes to avoid injury and will now prepare for Wimbledon at her home in Florida.
After losing to Safina in the fourth round of the French Open, Sharapova lost her number one ranking to French Open champion Ana Ivanovic.