Maria Sharapova's first opponent following her return to tennis after a 15-month doping ban has questioned the decision to give the Russian wildcards for several WTA tournaments.
Sharapova, 30, is scheduled to play Roberta Vinci of Italy in the first round of the Porsche Grand Prix in Stuttgart on Wednesday.
"I don't agree about the wildcard here and about the wildcard in Rome and the other tournaments," said Vinci, 34.
Sharapova was handed a two-year ban last year, backdated to 26 January 2016, after she tested positive for the drug meldonium at last year’s Australian Open.
The Court of Arbitration for Sport later reduced the suspension to 15 months following an appeal.
The world number 36 Vinci added: "She made her mistakes for sure, but she paid and I think she can return to play – but without any wildcards."
Poland’s Agnieszka Radwanska, who could meet Sharapova in the second round, has also questioned the former world number one’s special treatment, saying she should not be given entry into Grand Slams.
Meanwhile, former world number one Caroline Wozniacki of Denmark has labelled Sharapova’s entry "disrespectful".
Sharapova's agent Max Eisenbud has hit back at her critics, calling the younger Radwanska and Wozniacki "journeyman" rivals who want to prevent Sharapova from playing at the French Open as it would affect their "last chance to win a Slam".
Sharapova, a double French Open champion, is unranked and needs a wildcard to compete at Roland Garros.
The French tennis federation has yet to make a decision on her participation.