Pain is the most obvious partner but then there is boredom and the mental anguish that comes with watching the world go on turning while you stand still. Topping it all off is the physiological downside.
‘Camp belly’ is the term the Irish players have coined for those injured guys stuck to the sidelines for spells during the Six Nations but whose prodigious eating has carried on regardless of such an inconvenient state of affairs.
Mike McCarthy has been struggling with that for the last fortnight, since he strained medial ligaments in his right knee against England, and he tends to find restraint particularly difficult when fajitas are on the menu.
Food has been on McCarthy’s mind quite a bit this last year or so, ever since Declan Kidney and the Irish brains trust gave him a list of adjustments he needed to make if he was to ever sit at the top table of international rugby.
Putting on a few pounds was paramount if he was to be transformed from a decent provincial lock with Connacht to a Test titan, particularly given he was tagged as a man to play on the tighthead side of the scrum, which requires that bit more beef.
“To play on the tighthead side I had to put a small bit of weight on and I am still trying to keep it on,” he said prior to Saturday’s meeting with France.
“I put a couple of kgs on, basically, and I will keep that on as long as I can carry it and maybe even put on another couple.”
Problem is there is good weight and bad weight but McCarthy’s body fat ratio has been helped no end this last week with three training sessions that produced no complications with his knee after sitting out the Scotland defeat.
It must have been a particularly galling time to break down for a man who had waited so long for his big chance at that level but he knows too that the injury could have involved a much longer hiatus from the game so he is grateful too.
“I’m 100%,” he confirmed. “It has healed up very quickly. I got through training [Tuesday] and I got through it [Monday] and trained with the boys on Friday and had no problems so, yeah, it’s 100%.
“I was maybe doubtful [for the France game] last week because I had to get through the three sessions and now that I have done them, there have been no problems after training so, yeah, feeling really good.”
That is good news because the timing and impact of his arrival as a top-class international operator — and that of Donnacha Ryan — has been immaculate.
Paul O’Connell and Donncha O’Callaghan have earned 76 caps during the Kidney era alone, which amounts to just four less than the other 10 locks who have worn the four and five shirts this past five seasons, but age and injury have crept up on them.
McCarthy and Ryan may be no spring chickens themselves but they have played comparatively little rugby compared to the aforementioned incumbents and are thus all too able to appreciate their current surroundings.
McCarthy, in particular, has come a long way. A former England U21 international who started out as a winger, he was still calling himself a flanker by the time he left Wasps a decade ago.
His departure at the time owed to a queue for jerseys that consisted of Lawrence Dallaglio, Joe Worsley and Paul Volley and to the promise of regular rugby on the west coast of Ireland which he has called home for two different spells.
He will depart again this summer with Leinster thedestination, another upward curve on a graph that had remained horizontal for so long.
“I am looking forward to a new challenge,” he admitted. “They have a great squad and massive strength in depth and I know that if you are not performing, you won’t be playing”