Flannery, who has 32 appearances to his name in Europe's premier competition, played for All-Ireland League side Shannon on Friday and came through a rigorous training session today to prove his fitness ahead of Saturday's clash.
And after missing more than four months with the calf injury, Flannery is thrilled to be back.
"My last game was the Barbarians match, so that was the bones of four months ago," Flannery told the Limerick Leader.
"I was delighted to get onto the field and very grateful to Shannon for giving me the opportunity to get some rugby,"
"What it came down to was that a nerve was getting pinched in my back. That was why I kept tearing my calf. We didn't figure this out for a while. The feeling was this is a calf injury, it shouldn't be dragging on this long. So that is why I got the anti-inflamatory injections in the spine. It was help to soothe and nerve and fix things. It has worked so far.
"Everything has gone well so far.
"There is a lot of rugby to play. The trick now is to try and stay fit. There is a lot of competition everywhere for places. If you are not fit, you are not even considered.
"Hopefully, I will be considered for selection. They may want me to play some more club rugby or they may want me involved in the game with Toulon. That is up to the management team."