Bernard Tomic and Matt Barton are in a holding pattern as rain threatens to cause havoc to the day-three Wimbledon schedule.
The two Australians were due to resume their first-round matches in the opening contests on Wednesday but the covers are on all courts at the All England Club.
Tomic is all locked up at two sets apiece with Spaniard Fernando Verdasco, while Barton is deep in a second-set tiebreaker after dropping the opening set against French qualifier Albano Olivetti.
After dropping the opening set and looking in strife, Tomic appeared to have wrestled control before dropping the fourth set and the 19th seed will be serving when play continues at 4-6 6-3 6-3 3-6.
Barton is trailing Olivetti 6-7 (7-9) 6-6 (5-5) in his Wimbledon main-draw debut.
The pair are bidding to join fellow Australians Nick Kyrgios, John Millman, Daria Gavrilova and Samantha Stosur in the second round.
Kyrgios opened his campaign on Tuesday with a typically lively 6-4 6-3 6-7 (9-11) 6-1 win over Radek Stepanek, Millman edged out Albert Montanes 7-5 4-6 5-7 6-4 6-3 and Daria Gavrilova rallied for a spirited 2-6 6-3 6-4 victory over Qiang Wang.
Stosur beat Magda Linette in straight sets on Monday and is scheduled to take on former finalist Sabine Lisicki in the fourth match on showcourt 18 on Wednesday.