Maria Sharapova
Sharapova returns to competitive action at Stuttgart on Wednesday Reuters

Maria Sharapova's first-round opponent in this week's Porsche Tennis Grand Prix in Stuttgart, Roberta Vinci, has spoken against the former world number one being given wildcard entries on Women's Tennis Association tour.

The Russian superstar returns to competitive action after serving a 15-month-suspension for taking taking a banned substance, meldonium, at last year's Australian Open. The initial backdated suspension period was two years but the ban was reduced after Sharapova appealed to Court of Arbitration for Sport (CAS) last October.

Sharapova, who has earned a wildcard to enter the main draw of Stuttgart, will face Vinci, who is best known for halting Serena Williams' quest for a calendar Grand Slam when she defeated her at the 2015 US Open semi-final, in the opening round tomorrow.

The 34-year-old has echoed the thoughts of her counterpart Caroline Wozniacki, who had earlier said that rules were being twisted and turned to favour the Russian player, who according to her, should start from the bottom again instead of receiving wildcards.

"I do not have anything against her. She made her mistakes for sure, but she paid and I think she can return to play, but without any wildcards, any help," Vinci said, as quoted by the Daily Mail.

"I do not agree about the wildcard here and about the wildcard in Rome and the other tournaments. Probably she would play two or three tournaments and be in the top 30 for sure. Probably there are a lot of players who are agreeing with me about the wildcard."

No automatic entry into main draw at Roland Garros

Sharapova faces an uphill task to qualify for the main draw of Roland Garros as well as the three-time Stuttgart champion needs to reach at least the final this year to garner enough points before the 1 May deadline.

While she will be expected to receive more wildcards for upcoming clay-court tournaments in Madrid and Rome, the French Open organisers have refused a direct entry into the main draw, according to the Telegraph.

However, the news portal reveals that the chances of her getting a wildcard to the qualifying draw of Roland Garros are bright. While the absence of to-be-mother Serena is expected to take the sheen of the Grand Slam tournament, Sharapova's entry might serve as the necessary boost.