A four-month spell on the sidelines followed, with Allen forced to watch the RBS 6 Nations from afar, but he finally made his long-awaited comeback in defeat at the Ospreys late last month. He featured again against Ulster at the Arms Park a week-and-a half ago and is set to do the same when the Blues travel to Meggetland to face Edinburgh this Friday.
With the Blues out of the running for a play-off place in the RaboDirect PRO12, Allen has just four more games to show Warren Gatland his worth before the Wales head coach names his squad for June's trip south. But, while he admits there is plenty of work to do given the length of his time out, Allen hasn't hidden his desire to be on that plane and to be pushing for his second Test cap in mid-June.
"I hope I have got enough time to get a place on the plane to South Africa with Wales this summer. I knew when I came back I had six games and it was about me and how I perform," said Allen.
"I want to get better and better and see what happens with Wales. My personal goal is to get on the tour and it will be a great experience to go away if I can do that.
"The Wales rugby environment is so professional and when I had a taste of it in the autumn I learnt so much from then experienced players around me. I have played in South Africa in the Junior World Championships and it was a great experience. We lost in the semi-final to New Zealand, but it was a great place to play so I would like to go back.
"It's been a frustrating time for me after picking up the shoulder injury four minutes from the end of my full Wales debut. It was probably the last tackle I was going to make in the game. But the operation has gone well and my shoulder feels great now. I have had no issues, no pain in tackles, so it is looking good."
Things are also looking up for the Blues after the disappointment of a lacklustre performance at the Liberty Stadium was followed by a heroic effort against in-form Ulster.
Victory over the Northern Irish outfit has given the region a huge lift and Allen hopes the squad can now kick on in Scotland against a side who are six points and three places above them in the table.
"It is a tight ground up in Edinburgh and the atmosphere will feel close. Edinburgh have big threats and some big South Africans who are very direct so it will be a tough and physical game," added Allen, who is looking for a big finish to the season for both himself and the Blues.
"We don't have specific goals but the teams we are playing are all in and around us and we have got to look to win them all and push up the table as high as we can.
"It's been good to get back at the end of the season and playing again for Blues. I've got a few games to make an impression and it started well with victory over Ulster. It's now a case of getting my match fitness and sharpness back and helping us climb the table and get some wins.
"My comeback game against Ospreys was hard because, no matter how much training you do, nothing compares to a game. But I felt more like it against Ulster and it was a great buzz to get the big win in our final home game - it is what you miss when you have been out for four months."