He previously spent time abroad playing for Lech Poznan in Poland and Konyaspor in Turkey.
But Douglas recently told the Yorkshire Evening Post another move abroad would be “difficult" with a young family.
The 31-year-old Scotland international is also said to be open to a permanent switch to Blackburn following his loan there last season.
Left-back Douglas joined Leeds in a £3m switch from Wolves in 2018.
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