Leavy is now leaping ahead of Lion King O'Brien
Leinster openside and Tadhg Berine came up the hard way in 'straight out' brawls
There have been many dates proposed for Sean O'Brien's return from hip and shoulder problems for Leinster and Ireland this season.
After all, the Tullow Tank was the British and Irish Lions Test openside against New Zealand as recently as nine months ago.
The 31-year-old is still a superior option when he can reach optimum fitness.
This was reflected in the 80 minutes against South Africa and 64 minutes against Argentina last November to leave him as a certain starter for the Six Nations.
The hip operation required from the back-to-back Champions Cup matches against Exeter Chiefs ruined his plans for the beginning of the Championship.
This opened the door for Josh van der Flier to have his shot at getting and keeping the No 7 shirt.
Sadly he lasted just 37 minutes before his season was wrecked by a knee injury at Stade de France.
The 'next man up' mentality meant that Dan Leavy stepped on to the openside and completed the French game, and every minute of the next five in a glorious series.
When O'Brien did make it back for the Scarlets clash in the Guinness PRO14 last month, it was with the golden carrot of being involved in the Grand Slam decider.
His shoulder gave way in the first quarter and on Saturday night against Treviso it acted up again, preventing him from coming out for the second-half.
Coach Leo Cullen's admission that there was a soreness in the shoulder does not bode well for O'Brien's involvement against the Scarlets in The Champions Cup semi-final on Saturday.
"Seanie is such a high calibre player. We want him to play every week," said Leavy.
All the while, the 23-year-old has been busy bursting on to the international arena as the outstanding openside in the Six Nations, leaving one interesting supposition.
Were the British and Ireland Lions to head south for the summer, who would be front runner for the No 7 Test shirt?
At present, Leavy stands head and shoulders above anyone from Ireland, England, Wales or Scotland.
He has arguably moved from third-choice Leinster seven to first-choice in what used to be called the four home nations; quite the accomplishment.
The precarious nature of the position, though, means the next knock is never too far away.
The nature of the beast is to accept that personal preservation comes a poor second to the collective benefit of winning the ball in the name of winning games and, ultimately, silverware.
"That's just the way I've kind of always played," said Leavy.
"To some people it might look a bit dangerous, but it's just the way I've always been, particularly when I go for a ball. If you are second guessing yourself in the back row, especially as a seven going for the ball, you are going to hurt yourself. You are either all-in or you are out."
A sense of humour has led to his own self-deprecating comparison to 'Quasimodo', as his eyes have taken something of a big-match battering in recent weeks.
"I don't think the modelling career is going to kick off, so, you know, I'll take two black eyes to get through this game," he smiled.
Leavy has been given the window to grow as an all-rounder ahead of the twin threat from two of the game's best poachers in James Davies and former Leinster forward Tadhg Beirne.
"I think Scarlets have shown their calibre and quality throughout the season, not just the Champions Cup, but through the PRO14," he stated.
"They are littered with Welsh internationals and you throw in a Tadhg Beirne around the park and they are a serious handful."
There was a time, not so long ago, when Leavy and Beirne shared the frustration of making their way in the game. They were young guns out to make an impression against the likes of O'Brien in training.
"I've always held Tadhg in very high regard," said Leavy.
"Me and Tadhg were always in the yellow bibs when we were going through the academy. It used to be a straight-out brawl between me and Tadhg and all the senior players.
"We were trying to prove ourselves and they were trying to keep us down in the academy for as long as possible."
Now Leavy has risen to the top of the game and Beirne is on his way there.
Coach Joe Schmidt will be interested to see how Ireland's openside copes on the ground with the uncapped man he is considering taking to Australia in the summer.