Maria Sharapova's first opponent after her 15-month doping suspension says the Russian should not have been granted a wild card for the Porsche Grand Prix or upcoming tournaments.

Roberta Vinci, who will face Sharapova in a highly anticipated first-round match late Wednesday, does "not agree" with organizers giving Sharapova a free passage into the main draw of their events.

"She is a great player and I have nothing against her. She paid for her mistakes," Vinci said on Monday. "She can return to play but without any wild cards, without any help."

Sharapova's suspension for using heart drug meldonium after it was banned at the beginning of 2016, ends on Wednesday, just in time to enter the opening round of the indoor clay tournament she won three times in a row from 2012-14.

Vinci joined the likes of Caroline Wozniacki, Dominika Cibulkova, Agnieszka Radwanska, and Angelique Kerber in speaking out against wild cards for players who return from a doping suspension.

"I know (Sharapova) is important for the tennis, for the WTA, for everything," Vinci said. "She is a great person, a great player, a great champion, but this is my opinion."

The 36th-ranked Vinci, who reached a career high 10th a year ago, would try to forget about the wild-card debate when stepping on court on Wednesday.

"It's an interesting match for sure, a difficult match, a tricky match but I am happy. I am excited to play against Maria," the 2015 U.S Open finalist said. "For me it's a normal tournament. I am preparing all in the same way as (for) other tournaments. I will just play my game, stay focused."

Vinci expected "a lot of the crowd on Wednesday to be (cheering) for her. But I don't know about the players. A lot of players will agree with me on the wild card."

Vinci lost all four sets and scored only four games in total during her two previous matches against Sharapova, but those were played on hard-court, 10 and five years ago, respectively.

On a different surface and against an opponent who is lacking match play, the Italian fancied her chances.

"I know it's tough to return after a long time," Vinci said. "She is probably happy about her comeback ... but practice is a little bit different from a match. You have to be focused every single point."

Vinci planned to practice on center court early Tuesday, while Sharapova won't be allowed to access any tournament facilities before her suspension officially ends on Wednesday.

"This clay is fast. For me it is better that it's more fast than normal clay," said Vinci, who reached the quarterfinals last year before losing to eventual finalist Laura Siegemund. "I try to keep the good memories from last year and just enjoy the match. There's probably a lot of pressure for both of us."