Andy Murray's former coach Ivan Lendl says the pair split because of his own family issues and the difficulty of matching the Scot's Wimbledon triumph.
They went their separate ways in March after a two-year partnership.
Lendl, 54, said: "Just doing 20 weeks a year was hard. Andy, after his back surgery and winning Wimbledon [in 2013], needed more time not less.
"A lot of little things combined. When you win a big tournament like Wimbledon, it's not easy sometimes."
Czech-born Lendl revealed that travelling to Prague to see his elderly mother and looking after his teenage daughter had placed a strain on the time he could dedicate to coaching.
The eight-time Grand Slam winner, who was Murray's coach when he won the 2012 US Open and Olympic Gold, said in the Daily Telegraph that the pair tried to find a solution "but neither one of us could figure out how to do that".
British number one Murray, 27, appointed former women's world number one Amelie Mauresmo as his new coach in June, and ahead of the start of the US Open Lendl believes the Scot can win more Grand Slam events in the future.
"Andy's a great player," Lendl said, "He is fully capable of winning more majors. As for how the coaching situation works out, we don't know yet."
Despite his split from Murray Lendl has not ruled out a return to coaching.
"Maybe eventually, but it has to fit right," he added. " It has to be someone I feel I can offer something to."