The former Real Madrid midfielder has not featured for the former Premier League club for two months after suffering a foot injury.
However, Adkins has revealed that the Dutchman, as well as Danny Williams, are back in training.
"The lads who didn't play Saturday were on the pitch having a hard session after the game," Adkins told the club's official website.
"Royston Drenthe was out there, so too Danny Williams. First they need to be training so it's pleasing they're out there, and then build up a level of fitness.
"[Drenthe] has got to get fit, if you want to play football you've got to be fit. He hasn't been on the pitch or trained for eight weeks."
Drenthe joined Reading in the summer.