The 20-year-old winger has been kept at Spurs for the first half of the season as part of his development after loan spells at Queens Park Rangers and first club Leeds United.
But Jose Mourinho is expected to give the green light to an exit now and Stoke are at the front of a queue of Championship clubs.
O’Neill has already brought in Rabbi Matondo on loan and the arrival of left-back Rhys Norrington-Davies gives the option of reverting to a 4-3-3 that hasn’t been possible since Morgan Fox suffered a hamstring injury just before Christmas.
Clarke, a tall and skilful wide man, burst onto the scene with a super-sub tag in 2018/19, Marcelo Bielsa’s first season at Leeds, and earned a £10m move to Tottenham the following summer.
He has only started four league games so far in his career but has made three sub appearances this season under Mourinho, two in the Europa League and one last weekend in a 5-0 FA Cup romp at Marine.
Stoke are also hoping to tie up a deal for Alfie Doughty by the end of the week.
The 21-year-old winger is currently sidelined with a hamstring injury until at least the end of January but will be allowed back on loan to Charlton, who are pushing for promotion from League One.
He has been a man in demand, with a contract set to expire in the summer meaning that Rangers and Celtic were hoping to lure him north for a compensation fee. There has also been interest from QPR, Brighton and Bournemouth.
But O’Neill had tried to sign him last summer and sees his super pace as a long-term major asset at the bet365.
Clubs in England, Belgium and Holland are on alert over the status of Thibaud Verlinden, who has only played eight minutes this season.
Verlinden made a comeback with the under-23s after seven months out with knee ligament damage and has been part of the first team squad recently without being able to make the final breakthrough into the starting XI.
The 21-year-old winger has made it no secret that he is desperate for game time but there have been no behind-the-scenes fall outs.
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He spent the first half of last season on loan at Bolton and another loan seems like the most likely option, with business expected to speed up across divisions and countries over the next couple of weeks despite the challenges of Covid and Brexit.
Exits are still vital for Stoke and Kevin Wimmer and Moritz Bauer, as well as Liam Lindsay and Tom Ince, could find new clubs before the deadline on February 1.