Ivan Lendl returned to coaching duties with Andy Murray for the first time in over two years on Tuesday.
The Czech-born American took charge of an hour-long coaching session at Queen's Club in London.
Murray is scheduled to play France's Nicolas Mahut in his opening match at the Aegon Championships at around 13:00 BST.
However, their practice session was cut short by rain and more is forecast throughout the day.
Lendl arrived from the United States on Monday evening, having last week agreed a deal to resume his coaching role alongside Murray.