Andy Murray predicted scheduling trouble for future late-season ATP events once the World Tour Finals leave London after 2013, with the new compacted annual calendar likely to force some hard choices among players.
The fourth-ranked Scot spoke before his second-round start at the Paris Masters, a week after leaving organisers in Basel, Switzerland, high and dry by withdrawing with a back injury from that event.
Now Paris Bercy and tournament director Guy Forget is paying the price as well with the injury absence of world number one Roger Federer, which leaves Novak Djokovic on course to top the year-end rankings for the second straight year.
Djokovic lost the ranking to the Swiss on July 9 after 53 weeks when Federer won his seventh Wimbledon title.
But the ATP said that Federer ended any chance of a return to the year-end top spot as he lost the weekend Basel final to Juan Del Potro and then withdrew from Paris with niggling injuries.
Djokovic started the year by defending his Australian Open title and boasts a circuit-leading 70-11 match record going into Paris.
With the race for the final two spots in the year-end event going down to the wire in Paris before Monday's start of the eight-man wrap-up, injury retirements figure in the equation as well.
In Valencia a week ago, London contenders Jo-Wilfried Tsonga and Janko Tipsarevic both quit first-round matches in pain.
Murray said that with the London season-ender starting next Monday without a gap between the end of Paris and the first round-robin match in the British capital, players are unlikely to be willing to risk playing three weeks in succession.
That was not the case until this year, when the ATP -- bowing to perceived player demands -- squeezed an extra two weeks of play out of the calendar, yielding an ending on November 12.
"With the way the schedule is just now, I think when the Tour Finals moves from London to a different continent I think there are big issues potentially with that," said Murray, third seed at the Bercy arena behind Djokovic.
"Guys (who could qualify seven, eight or nine) are not going to fly all the way to a different continent if there is a chance you're not going to get in (the year-end event), not find out until Sunday probably and potentially have to play on Tuesday."
The finals are to stay in London at least until 2013 but the venue thereafter is subject to big-money negotiations.
Murray said that not having the traditional rest week before the year-end finals is making life complicated.
"It's probably going to affect a couple of the tournaments, but that's what happens when you take a couple of weeks off the Tour. It's never going to be perfect.
"Basel, Valencia (the same week), and Paris and having a week off and then playing the Tour Finals is fine. But it's going to be tough to play all three back to back with obviously most guys' main priority wanting to be fresh for the finals."
Murray pronounced himself fit after two weeks of no tournament play following his loss to Djokovic in the Shanghai final.
"I had a full week rest after Shanghai, which I needed," said the US Open and Olympic champion who admits that his focus is on the London week after failing to complete a year ago owing to injury.
"I just started to build up my training gradually. We came here on Friday so I have had pretty decent preparation for the tournament, which is good.
"I picked up a bug on the way to Asia and still didn't get rid of it until a few days after I got back. It was important to rest.
"Now I feel better coming to Paris than I did last year."
With all 16 seeds in the field given first-round byes, matches went ahead with lesser lights Monday.
In first-round play, Italy's Andreas Seppi beat Martin Klizan 6-2, 2-6, 7-6 (7/5) while South Anderson Kevin Anderson beat Brazil's Thomaz Bellucci 6-2, 6-1.
Carlos Berlocq stopped Denis Istomin 7-6 (7/2), 6-2 and Polish qualifier Jerzy Janowicz defeated German Philipp Kohlschreiber 7-6 (7/5), 6-4.