The 27-year-old has a host of international experience, having lifted the RBS 6 Nations Grand Slams in both 2008 and 2012.
He is expected to replace Newport Gwent Dragon Andrew Coombs, who has deputised admirably for Jones in the opening three fixtures.
Having lost at home to Ireland in the opening weekend of the Championship, Wales have since strung back-to-back wins together over France and Italy.
While a victory over Scotland at Murrayfield this weekend would set-up a potentially mouth-watering RBS 6 Nations decider against England at the Millennium Stadium in the final round of fixtures.
"Alun Wyn coming back gives us more strength in that department," said Wales defence coach Shaun Edwards.
"He came back through last season's Six Nations as well and made a good impact.
"You want your best players fit. At one stage we were pretty short of our recognised starters at the start of the Six Nations in that position
"But [Andrew] Coombs, in particular, has done very, very well. Alun Wyn coming back gives us more strength in that department."