Burnout - which Premier League players could be most at risk?
Romelu Lukaku has played the most football of any Premier League player this season going into the festive schedule that is troubling his Manchester United team.
A widely-discussed post on United's website this week suggested they face a bigger problem with player burnout over Christmas than the league's other leading sides, with only "six non-matchdays" between December 23 and January 1.
Manager Jose Mourinho has labelled Lukaku "untouchable" but may have to rethink that stance - the Belgium striker has played every minute of the league season, with a heavy Champions League workload taking him to 2,287 minutes in all.
Lukaku spearheads a most-used Premier League XI which also features team-mate Nemanja Matic - though Manchester City (Nicolas Otamendi and Kevin De Bruyne), Tottenham (Eric Dier and Jan Vertonghen) and Chelsea (Cesar Azpilicueta and Marcos Alonso) also contribute two outfield players apiece.
Everton's Ashley Williams and Liverpool's Mohamed Salah also feature and, while b urnout is less relevant to goalkeepers, Chelsea can lay claim to a third representative or Everton a second.
Thibaut Courtois and Jordan Pickford are tied on the maximum 1,620 Premier League minutes and 630 in other competitions.
Europe takes its toll
The clubs dominating the list are those in continental action - Williams has played 1,204 Premier League minutes, less than 13 and a half of Everton's 18 games, but a further eight full matches in the Europa League make him the third-most used outfield player.
Second-placed Azpilicueta - who played every minute of Chelsea's title-winning campaign last season - has missed only November's game against Swansea and 17 minutes of the Champions League group stage.
Nine outfield players have already broken 2,000 minutes in all competitions, with Otamendi 40 minutes short of the landmark.
Press Association Sport also filtered the data to look at players who have played the equivalent of the full Premier League season so far, at least 1,620 minutes.
United have five such players but pale in comparison to their rivals, with eight from Liverpool and seven apiece from City and Chelsea. Entering the Europa League at the qualifying stage puts Everton out in front with nine, while Spurs have six.
Klopp shuffles his pack
Looking at league minutes alone, Liverpool are the only team for whom not a single player has played for 90 per cent of the season - even keeper Simon Mignolet has missed two games.
Six Leicester players and five each from Spurs, Brighton and Huddersfield have achieved the mark, with United, City and Arsenal among six teams with four.
That tallies with the 23 Premier League ever-presents so far. Brighton contribute four in Mat Ryan, Lewis Dunk, Davy Propper and Dale Stephens, while Arsenal (Petr Cech, Hector Bellerin and Nacho Monreal) and Leicester (Kasper Schmeichel, Wes Morgan and Harry Maguire) have three apiece.
Burnley are about to lose one of their two ever-presents, with James Tarkowski's suspension leaving Jack Cork to stand alone. David De Gea joins club-mate Lukaku, while Huddersfield (Jonas Lossl and Mathias Jorgensen) and Swansea (Alfie Mawson and Lukasz Fabianski) also have two.
Watford midfielder Abdoulaye Doucoure and keepers Asmir Begovic (Bournemouth), Fraser Forster (Southampton), Courtois and Pickford complete the list.