The versatile Aberdeen player has been missed during his four-month spell on the sidelines, which has coincided with the Dons sliding from a point off the top of the SPL to the bottom half of the table.
But Jack has been given the green light to return to a Reds midfield that has looked distinctly one-paced in his absence, and is determined to reverse the slump.
He said: “It has been frustrating seeing the team dip and it’s important we come through this spell and start winning games again.
“Every match is a dogfight now and we have to make sure we are up for it.
“I’m back at a good time and hopefully we can make the top six and qualify for Europe. It is massive for the players, the manager and the club to get there.”
Jacker's last match for the Dons before injury was against today's opponents Kilmarnock at Rugby Park, and the Scotland Under-21 captain is looking for a similar result to the Reds' last visit.
"We won 3-1 down there earlier in the season so hopefully we can do it again,” he said.
Source: Aberdeen Mad