The point at which the up-and-coming man becomes the established player, there to be shot at, is not always obvious. The remarkable impact made by Joe Launchbury for England against first South Africa and then the All Blacks during the autumn internationals, however, made it apparent to Courtney Lawes that it may just have arrived.
Still covered in mud from the training field, the giant Northampton Saint smiles a little wryly.
"Yeah. I sort of thought I was the top-pick second row going into the autumn internationals, then I'm injured again in the game before we were set to go away and the next thing you know there's a young buck who has come in and taken my place," said Lawes, at 25 only four years older than Launchbury.
"It was a frustrating end to what's been a pretty frustrating year, but at least it's ending on an encouraging note."
By which Lawes means he is fully recovered from the last of the four injuries he suffered in 2012, and he got on the field for long enough to share the euphoria when England closed out a first win in 10 matches against New Zealand earlier this month.
His match fitness, both physical and mental, remains a work in progress, however, and in Launchbury, Lawes knows he now has a rival not just for his England starting place but for the Lions shirt that once seemed his for the taking for next year's tour of Australia. The Lions' forwards coach, Graham Rowntree, made it clear in his post-match comments that Launchbury, assuming he maintains his startling form, is very likely to travel.
Lawes knows too that everything starts with his club form, and that Northampton, like England, need him to be at his best. A poor week's training, including a couple of days of sickness, led to Lawes being left out of the starting line-up for the Saints' Heineken Cup trip to Ulster in mid-December. As luck would have it, however, injury to flanker Gerrit-Jan van Velze resulted in Lawes being sent on after just 22 minutes, and the quality of his performance in defence suggested that being named among the substitutes, along with a lecture from the forwards coach Dorian West, had had the required effect.
"My intensity hadn't been there in training, I think because I'd sort of got out of the habit of it because I've been injured so many times," admits Lawes.
"Sometimes it takes someone to tell you for you to get your head around it and say to yourself 'Come on, pick it up,' and that's what happened. I didn't expect to be on there that early against Ulster but I got on and was able to give a good performance.
"I know I'm a good enough player, on top form, that I'm going to get picked, but that's what I've got to make sure, that I'm the best as I can be. 'Westy' has sort of flicked a switch back on in my head, and now I'm going on over the rest of the season knowing what I have to do to get my place back."
For Northampton's director of rugby, Jim Mallinder, the domestic games running up to the Six Nations Championship are among the most important Lawes will have played.
"Up until now Courtney has been the young player coming through, but now he's really got to show he's become the player he promised to be," said Mallinder. "He wants to and I'm sure he will, but before he does it for England he has to do it for Saints.
"He needs to put a run of games together, and if he does that I've no doubt he can be even better than he was before. He's matured physically, he's worked really hard in the gym, and in terms of his all-round game, his understanding, that's improving all the time, and will only get better."
Staying fit will be key. With a grimace Lawes recounts the sequence of injuries which made 2012 such a stop-start year.
"First I ruptured my medial ligament in my right knee, that was against Newcastle on New Year's Eve and put me out for six weeks.
"I came back and played three games, but in the second game I picked up a stress fracture in my shin which put me out for four months. Then in pre-season I dislocated my elbow in training – just put my arm out as I fell and dislocated it – and that was two months out, then I played six weeks, then in the first 10 minutes of the game against Sarries I picked up a grade two on my left medial ligament, which wasn't too bad but still meant another three weeks out."
For Mallinder, Lawes is the type of player who will inevitably pick up occasional injuries.
"When you play like he does there is always a chance. He's a very tall, big man who commits, who puts 100 per cent into everything, particularly his carrying and his defence, his tackles, and in that case you will pick up knocks. But luck is a factor, and his hasn't been great in 2012."
It is worth noting, however, that the game at Ravenhill was Lawes' 100th for Northampton. As West points out, it's easy to forget he joined Northampton's senior academy not much more than five years ago.
In some respects, his athleticism, married to his extraordinary power in the tackle and adept ball-handling, has already redefined what is expected of an England lock. Having set such high standards, however, it was probably inevitable that for whatever reason Lawes would have a spell when he found them hard to maintain, let alone improve on.
If, as he maintains, that time has been and gone, it can only be good news for England. "For me now, the only way to get better at rugby is by playing.
"At the age I am, I should be as fit and strong and quick as I'm going to be, so I need to be out there. And over the next few weeks, that's where I intend to be."