Chelsea are said to be the frontrunners for the free-scoring Norwegian, who could cost in excess of £150m if he leaves the Westfalenstadion this summer.
With Dortmund realistically against the idea of part-exchange deals, that asking price could rule out the rest of the competition for his signature.
Nevertheless, according to reports in Spain, United are ready to tempt Dortmund into signing Martial now that he has fallen down the pecking order at Old Trafford.
The France international contributed just four goals and three assists from 1,488 minutes of Premier League football during the last campaign.
Ole Gunnar Solskjaer is prepared to consider offers for the 25-year-old, who has a contract with United until 2024. body check tags ::