John Millman’s tennis year looks to have come to an end after the Australian retired following the first set of his opening round match at the Paris Masters.

The US Open quarter-finalist has endured a steady stream of injuries over the years and appeared hampered by a back problem part way through the match against hard-hitting Georgian Nikoloz Basilashvili.

Millman was heard to say he was struggling to serve and received painkillers and strapping to his back when down 4-3 in the first set.

The Australian No.2 pulled the pin after losing the set 6-4.

Millman missed much of 2017 through injury but has had a strong 2018, moving up to No. 35 in the world.

He defeated Roger Federer to reach the last eight at Flushing Meadows, made the final of the Hungarian Open back in April and was recently short-listed for ATP comeback player of the year.

But pickings have been slimmer since his remarkable US Open, the Queenslander winning just the one match in four tournaments since.

Karen Khachanov was an early first-round winner in Paris on Monday, beating Filip Krajinovic 7-5 6-2.

Australian No.1 Alex de Minaur features later on Monday against Feliciano Lopez.