When measured by the number of minutes played, at least half a dozen of Leinster’s frontline players have not been playing for their province during Pro12 weekends for an average two games out of every three, or, 66 per cent of the time.

Of nine Leinster and Ireland players just Luke Fitzgerald played more than 40 per cent of the time in Leinster's games in the league until their defeat to Ulster last week.

Leinster have played 20 Pro12 matches (1,600 minutes) and have two remaining before the knock-out stages.

None of the other frontline players including Rob Kearney, Mike Ross, Devin Toner, Jordi Murphy, Cian Healy, Seán O'Brien, Jamie Heaslip or Jack McGrath played more than 35 per cent of the game time so far in the competition.

Ian Madigan has played almost half of the total time, 777 minutes in 12 games.

Players who were out of rugby with long-term injuries such as Healy and O’Brien dipped below the 20 per cent mark. O’Brien, who suffered a complicated shoulder injury, has played just 150 minutes of the Pro12 season, or 9.3 per cent of the available game time.

Healy’s pitch time came in at 19.8 per cent, which represents 316 minutes over seven matches, with Ross playing in six league matches for a total of 346 minutes, or, 21.6 per cent of the total time.

Best rest

A number of factors come into player availability, not least injury and Ireland demands – which ensures the best rest. Those player-welfare concerns may point to Paul O’Connell’s low turnout of 29.3 per cent for Munster’s Pro12 campaign.

Leinster’s two extra matches in Europe would also have drawn on international player resources, which would have affected Matt O’Connor’s ability to pick them for Pro12 games.

O’Connor’s side were the only Irish province to make it out of the pool phase in the Champions Cup and played additional games against Bath and a semi-final against Toulon in Marseilles.

Ireland's call over the course of the year is a significant factor, not only the November series and Six Nations Championship but also Joe Schmidt's plans at this year's World Cup.

International matches for the entire year, including the friendly games in August, will have been factored into the equation and as Leinster provide maybe six Ireland starters – Healy, Ross, Toner, O’Brien, Heaslip, Kearney – and more on the bench, they are hardest hit.

In that respect Ulster come out well. Tommy Bowe and Rory Best are first picks for Schmidt but their Pro12 profile is strong.

Bowe has played 43 per cent of the time and Best 46 per cent, while Paddy Jackson, Craig Gilroy and Darren Cave, who were largely out of Schmidt's Irish thinking for various reasons, have played for about 50 per cent or more of Ulster's game time, Gilroy playing 78.6 per cent so far.

Centre Jared Payne, however played in just six Pro12 matches, which accounts for only 24.7 per cent.

Recently a difference of opinion emerged between Schmidt and O’Connor with Schmidt arguing that the welfare scheme plays a huge role in convincing players such as O’Brien to remain in Ireland and persuading Johnny Sexton to return.

He pointed out that two years previously when he was in charge during the Six Nations period Leinster earned 18 out of 20 available points. Last year O’Connor got 19 out of 20 available points, while this year that figure dropped to nine.

Pro12 Frontline players’ game time

Total number of Pro12 games played so far is 20 (1, 600 minutes)

Leinster

Seán O’Brien (played 2) – 150 mins 9.3%

Cian Healy (7) – 360 mins 19.8%

Mike Ross (6) – 346 mins 21.6%

Jack McGrath (8) 398 mins 24.8%

Rob Kearney (8) – 522 mins 32.6%

Jamie Heaslip (8) – 525 mins 32.8%

Jordi Murphy (9) – 538 mins 33.6%

Devin Toner (8) –552 mins 34.5%

Luke Fitzgerald (10) – 663 mins 41.4%

Ulster

Iain Henderson (5) – 334 mins 20.8%

Chris Henry (8) – 559 mins 35%

Tommy Bowe (9) – 689 mins 43%

Stuart Olding (13) – 707 mins 44.1%

Rory Best (11) – 742 mins 46.3%

Paddy Jackson (11) – 785 mins 49%

Darren Cave (18) –1,215 mins 75.9%

Craig Gilroy (17) – 1,258 mins 78.6%

Jared Payne (6) – 396 mins 24.7%

Munster

Paul O’Connell (6) – 470 mins 29.3%

Peter O’Mahony (7) – 412 mins 25.7%

Keith Earls (8) – 556 mins 34.7%

Ian Keatley (17) – 1,189 mins 74.3%

Felix Jones (12) – 853 mins 53.3%

Simon Zebo (11) – 851 mins 53.1%

Tommy O’Donnell (12)– 765 mins 47.8%

Conor Murray (8) – 580 mins 36.2%