Law, who has stepped in to fill the job left by outgoing coach Trevor Bayliss, has a tough assignment ahead as Sri Lanka leave for a gruelling tour of England on Tuesday.
The touring squad will be without eight players, including new skipper Tillakaratne Dilshan, who are in India for the money-spinning Twenty20 competition.
"It (IPL) is a can of worms," Law told AFP, when asked if it was right to ask Sri Lankan players to leave the IPL midway through to tune-up for the England tour.
"The way I look at it is this. All our boys are playing competitive cricket right now in IPL. They are playing a high level of competition, working under different coaches. It''s better that way than having training."
Sri Lanka Cricket had earlier ordered its IPL players to return home early and train for the tour comprising three Tests, five one-dayers and one Twenty20 internationals.
The board later backed down and asked the players to join the team in England on May 18 ahead of the second practice game in Derby.
Law, a former Australian batsman, said cricket boards in England and Australia had the financial resources to retain their players and ask them to skip IPL for national duty.
"But in Sri Lanka, we can''t afford that," he said. "The IPL won''t go away. It''s huge. It is shown around the world.
The boards will have to come up with a compromise, a definite window to accommodate it."
Law said it would also be unfair on the franchises if players skipped the tournament midway.
"From a player''s point of view, a definite window will be helpful," said Law who had been assisting Bayliss since 2009.
Law, however, admitted that the IPL has hampered the team''s preparations with the selectors being forced to rope in Farveez Maharoof and Kaushal Silva as cover for missing senior players.
Maharoof is currently playing county cricket with Lancashire, making an impressive start to the season with a hundred on his debut against Somerset at Liverpool.
Silva, 24, is uncapped but has an impressive first-class average of 45 and has been picked up as a back-up for Prasanna Jayawardene.
The first Test begins in Cardiff on May 26.