The Tottenham Hotspur midfielder has been tipped as a transfer target for both Hoffenheim and Borussia Monchengladbach, according to the Sun.
Spurs were said to be considering recalling Onomah from his season-long loan at Hillsborough to help with their injury crisis, but the 21-year-old is set to return to S6 this week after a short spell out through injury.
Monchengladbach are said to be monitoring Onomah as they expect to lose midfielder Denis Zakaria this summer.
Onomah has not played for his parent club since April 2017, but was a favourite of incoming Owls boss Steve Bruce while on loan at Aston Villa last season as he made 37 appearances in all competitions.
This season the midfielder has played in 11 Championship matches for Wednesday, providing three assists.