The 20-year-olds have been unable to play competitive matches for Dario Gradi's men since returning from loan spells in Iceland in October due to international regulations.
However, after receiving confirmation from the Football Association and the Football League, the duo are now available.
Both are pressing for first-team places with Betts in real contention with Adie Moses, Chris McCready and Richard Walker all injured.
The pair both spent time with Icelandic side IBV, who were favourites for relegation but finished a more than respectable mid-table.
