Andy Murray will make a final decision on Tuesday as to whether he is fit enough to play in the Wimbledon singles later that day.
The 37-year-old Briton, who had a cyst on his back removed nine days ago, is scheduled to play Tomas Machac of the Czech Republic at about 18:30 BST.
Murray is giving himself as long as possible to be ready to play in what will be his Wimbledon farewell.
The two-time champion is planning to retire later this year.
If he is not fit enough for one final appearance in the singles, Murray could still play in the doubles alongside older brother Jamie later this week.