As antiquated terms such as 'wing-half' disappear from footballing vocabulary, so others spring up to take their place. 'In the hole' has now become commonplace, along with 'the Makelele role' and 'support striker', while there could also be another addition with the concept of an impact substitute becomingly increasingly popular.
It is growing in currency, but it is not a novel idea as Liverpool's David Fairclough excelled in the role the best part of three decades ago. Yet as Ole Gunnar Solskjaer, the deadliest replacement of the Premier League era, heads off into retirement, his legacy is apparent on the benches of several clubs.
If Solskjaer's success was attributable, in part, to his ability to analyse a match before his arrival, it would suggest that the role of the impact substitute was best suited to footballing pensioners, lacking the legs for 90 minutes, yet capable of exerting an influence for a briefer period.
However, it now seems to be the preserve of the youthful, bursting with energy and keen to impress in their cameo. Although some matches have been changed with the introduction of high-calibre players - such as Fernando Torres against Fulham or Carlos Tevez versus Sporting Lisbon - neither qualifies as an impact substitute. They were automatic choices, briefly demoted for reasons of fitness or squad rotation, rather than specialist substitutes. Nor do Tottenham's third and fourth choice forwards count; Darren Bent and Jermain Defoe rank among the frustrated, coveting the starting spots.
In contrast, Louis Saha's role as an impact substitute may be enforced. The fragile Frenchman rarely appears capable of completing 90 minutes, so saving him for a potentially decisive finale is an idea with merit. His potential to make a difference is enhanced by his obvious differences with the strikers who start for Manchester United, Tevez and Wayne Rooney.
Saha is naturally happier leading the line and, more accustomed to running in behind opposition defences, can effect a change in the gameplan by providing another element to the United attack. It is no coincidence that both of his goals this season - against Sunderland and Chelsea - have come when he was a substitute, whereas recent starts against Bolton and Sporting Lisbon have been unprofitable.
Liverpool can recount a similar story of their impact substitute. When Ryan Babel was promoted to the starting line-up against FC Porto, he produced his most ineffective display for several weeks. However, as a replacement, he made four entertaining cameos in as many games, yielding a quartet of goals, two against Besiktas and, following an important contribution against Fulham, one apiece against Newcastle and Bolton. At £11million, Babel may appear expensive to be deemed a replacement, but as eight of his 12 Premier League appearances have come from the bench, it suggests that Rafa Benitez feels he is best utilised as such.
Arsenal's Theo Walcott is yet to produce the firm evidence, in the form of goals, but there is a school of thought that he is also at his most productive when a late entrant to the proceedings. Versatility helps, with the option of deploying the youngster on the left, the right or as a central striker according to Arsene Wenger's needs, and he could yet adopt a similar role for England. It marks a change of approach from Wenger, however; as a few years ago, his idea of an impact substitute appeared to be Gilles Grimandi, capable of playing several positions and invariably brought on to shore up the side when ahead.
Yet impact substitutes are by no means confined to the title challengers. Matt Derbyshire provides speed and zest from the bench for Blackburn where, with a strike partnership of the ability of Roque Santa Cruz and Benni McCarthy, first-team football is understandably hard to come by.
Derbyshire has a happy knack of making a telling contribution, as does Everton's Victor Anichebe. Indeed, David Moyes has voiced the opinion that the striker is at his best when brought off the bench. That certainly appears to be the case in Europe with first Metalist Kharkiv and then Nurnberg unable to deal with the replacement's bruising physicality at the end of an arduous game.
The common denominator among these five impact substitutes is pace and it is proof that even the quickest and fittest defences can tire as gaps appear in the closing stages.
That said, the impact substitute is the logical consequence of developments such as the widely accepted theory that four strikers are a necessity, or the need that every manager expresses for strength in depth. Indeed, with bloated squads growing with each transfer window, it also makes sense to give some of the supporting cast a specialist role of their own. To redefine them from fringe players to, in effect, specialist finishers who could change a game in the closing stages, makes sense.
Perhaps that is the fate of one of Tottenham's multitude of midfielders. Tom Huddlestone, conspicuously lacking the pace of the other impact substitutes, has not been granted a start by Juande Ramos so far. Yet, brought on at half-time twice within three days against Aalborg and Birmingham, he created a goal in both games, suggesting a passing midfielder can also adapt to the pace of the game immediately and could therefore be classified as an impact substitute.
At the other end of the spectrum, however, there is a less desirable role, that of the 'non-impact substitute'. At the moment, that appears to be Andriy Shevchenko's unwanted lot as he continues not to influence proceedings at Chelsea. If 'the Shevchenko role' is added to the football lexicon, it will not be as a compliment.