Opposition to Maria Sharapova's return to top level tennis via wildcards has intensified on the eve of her comeback at the Stuttgart clay court tournament.

Sharapova's 15 month ban for using the banned substance Meldonium expires today and she plays her first round match in Stuttgart tomorrow.

World number five Simona Halep says it's not ok to help a player banned for doping with a wildcard while French player Alize Cornet says she finds it shameful that the WTA is promoting a player who tested positive.

Meanwhile reports have emerged the French Federation is considering only giving Sharapova a qualifying wildcard into next month's French Open.