Coughlin is the world-record holder in the event and set the Olympic record -- 1 00.17 -- when she qualified on Sunday.
Hennie Otto, a 27-year-old South African who qualified on Monday, was leading the tournament after shooting a three-under-par 68.
"You want the focus and motivation as high as possible for any game but having qualified on Thursday – and enjoyed ourselves on Thursday night – there was always going to be an element of fatigue.
Ireland next face unbeaten India, who have already qualified, on Tuesday.
He will first have to get past Federer, who qualified on Thursday, or Del Potro, who could yet lose out to David Ferrer when Group B is concluded on Saturday.
In addition to Utley, Greg Buckner, Ben Bates, Lonnie Nielsen and Tom Byrum also qualified on Monday to play in the Toshiba Classic.
That means Fittipaldi must post one of the 36 fastest times in qualifying on Friday.
Although partners for the synchronised dive, Tom Daley and Peter Waterfield would have competed against each other for an Olympic medal if Waterfield had not failed to qualify on Friday.
Steve Osborne, 60, from the Isle of Man, came off at Alexander Drive, just before Quarterbridge, on the first lap of qualifying on Friday.
