QPR loanee Tom Carroll wants to "make it at Tottenham" but is prepared to consider all of his options at the end of the season.
Ilkay Gundogan has commited his future to Borussia Dortmund by signing a new contract.
Dawson was released after 10 years at the club and subsequently joined former side Scunthorpe.
The Iron have a League Two fixture at Bristol Rovers on the same date as the Betis match, August 10, but Dawson has been given permission to play in his own testimonial instead.
The 34-year-old played 317 times for Hull and was part of four promotion-winning sides.