|French Open - Murray v Karlovic|
|Venue: Roland Garros, Paris Date: Friday 26 May Time: Second on Suzanne-Lenglen Court (approx 12:00 BST)|
|Coverage: Live BBC Radio 5 live sports extra radio and text commentary on the BBC Sport website and app|
Andy Murray faces Croat Ivo Karlovic in the French Open third round on Friday after surviving five-set scares in his first two matches in Paris.
Second seed Murray has spent seven hours and 14 minutes on court against Radek Stepanek and Mathias Bourgue.
Davis Cup captain Leon Smith says Murray's good form before Roland Garros may be behind his initial struggles.
"If it doesn't quite go that way in the early rounds here, there's a bit of frustration," Smith said.
Murray's meeting with big-serving veteran Karlovic is the second match on Court Suzanne Lenglen on Friday at approximately 11:00 BST.
The British number one warmed up for the French Open by beating Novak Djokovic in straight sets in the final of the Italian Open.
But, by his own admission, Murray has been well short of that level in Paris.
He posted an image of a Get Out of Jail Free card from the board game Monopoly on social media after fighting back to beat against world number 164 Bourgue.
Smith, who was also a childhood coach of Murray's, says the 29-year-old could rediscover his form as suddenly as it left him.
"He had an unbelievable last match against Novak Djokovic and then suddenly the timing's not quite there," he added.
"That's what happens in this crazy sport. It literally changes every single day - yourself, the opponent, the conditions."
Karlovic, 37, became the oldest man to reach the third round of a Grand Slam event since Jimmy Connors at the 1991 US Open by beating Australian wildcard Jordan Thompson 12-10 in the decider of his own five-set epic.
The world number 28 is the top server on the men's tour, averaging 23 aces a match and winning almost 95% of his service games over the past year.
He has lost all six of the matches that he has played against Murray, most recently being beaten in four sets in the last 16 at Wimbledon 2015.
Another big server could await Murray if he extends that winning run over Karlovic. American John Isner is seeded to be his last-16 opponent.