A new and loaded term has popped up in the lexicon of world football over the past few years: rotation. Cursed by some and praised by others, the 'squad rotation policy' as employed by top clubs such as Liverpool and Chelsea and to a lesser extent Bayern Munich, Inter Milan, Sevilla and Lyon is a tactical system whereby a manager swaps players in and out of the first eleven based on fitness, fatigue, form, chemistry and the various strengths and weaknesses of the day's opposition.
Though it is true that coaches throughout history have always been forced to change their squads due to injury, suspension, illness or endless other external factors, the rotation policy of today is based on a principle of management, a pre-planned formula aimed at achieving success. It is, in many ways, a rational response to the rigours of the modern game, unprecedented fixture congestion and an attempt to keep a team winning and its players fresh.
"When you change players around, especially the big names, people will make comments," said current Liverpool boss Rafa Benitez, whose name has become synonymous with squad rotation. "You hear people talking about it all the time, but they don't know the situation as I do and I believe that by rotating the players they will be fitter later in the season and we will be stronger throughout."
This is the theory at least. There are, of course, opposing points of view on the subject.
"I'm not a fan of all this rotation," Stevie Nicol, a fixture in the all-conquering Liverpool side of the 80s and coach of MLS outfit New England Revolution, recently told FIFA.com. "I understand a manager trying to keep players fresh, but with all of the problems that all that rotating causes, they may have nothing to be fresh for come the season's end!"
"Look at Arsenal for example," Nicol added. "Wenger's team is leading the Premiership and he usually only makes changes that are forced on him."
Another by-product of any rotation policy is potential player dissatisfaction. "We all know that he (Benitez) likes to chop and change the squad," said Peter Crouch, one of the principal victims of Liverpool's rotation system, particular since Spanish hit-man Fernando Torres arrived at the start of the season to bring the number of senior strikers to four. "It's just something he (Torres) will have to get used to it... as long as we're winning you won't hear too many complaints."
Chelsea's huge squad is also, almost by necessity, a rotating entity. With a first team of 25 stars from 13 different countries, recently departed coach Jose Mourinho instituted a policy of week-to-week, cup-to-cup rotation - albeit with a few exceptions, notably Messrs Cech, Terry, Lampard and Drogba - to rival Rafa's Liverpool. Results followed too in the form of two English Premier League titles in a row.
While some players like Arjen Robben and Ricardo Carvalho criticised the policy openly, captain John Terry was quick to defend it as a source of necessary competition in the team: "If you get dropped from the starting eleven after two or three bad games, then you have to get your form, impress the manager and get yourself back in there," he said.
Rotation isn't only happening in England. Big-name, winning clubs all around Europe are employing the tactic to varying degrees. Bayern Munich boss Ottmar Hitzfeld has been tinkering with his squad, especially the defence, after a spending spree in the close season saw the his talent pool swell. One victim of the new policy - and the sparkling form of Luca Toni and Miroslav Klose - has been big-money signing Lukas Podolski.
"I know I can play football," the German international said recently when asked about his lack of playing time. "When I get my chance again I will show everyone." He may have done just that when, in for Toni from the start, he scored both Bayern goals in a 2-2 draw with Bolton on Thursday in the UEFA Cup.
Over in Spain, Sevilla - UEFA Cup winners two years running - are one of very few La Liga teams to employ a policy of regular squad rotation, certainly since the departure of Fabio Capello from Real Madrid. That said, with the mastermind of the system, Juande Ramos, now with Spurs in England, the future of squad rotation in Seville, however successful it has proved, could be in question.
In France, meanwhile, six-time consecutive champions Lyon have scaled back their usual rotation this year, but PSG and Rennes have both been swapping players in and out with increasing regularity. Despite the grumblings of detractors and the applause of its supporters, the decidedly modern incarnation of rotating squads will be judged just like everything else in football: by results.
"It's hard to have a go at a guy like Benitez and his ideas," concluded the sage like Nicol, a remnant of the days when a team could win titles with a firm core of eleven players. "After all, he's brought the European Cup back to Anfield."