Jamie Murray says tennis players are currently "walking on eggshells" with regards to making plans to compete on the ATP Tour.
Murray is back in London after a four-week stint in Australia, the first two of which were in quarantine where he was only allowed out of his hotel for five hours a day ahead of the Australian Open.
The doubles specialist, who got to the semi-finals with partner Bruno Soares, next intends to travel to tournaments in Mexico and Miami next month, but admits he is uncertain what is in store for him when he gets there.
"If there are quarantines in place it is almost impossible for tours to run. Australia was only able to do it because it was the first event of the year. If there are more quarantines in place the Tour basically cant function."
Murray has announced he will host the third instalment of the Battle of the Brits tournament in December.
The exhibition event was conceived during lockdown as a way for British players to get some action and it was a roaring success, with a follow-up edition last Christmas.
It will next be staged in Aberdeen, in front of fans, where Murray will team up with his brother Andy to stage a Scotland v England competition on 21 and 22 December.
"We are really excited by the event, it is going to be a lot of fun and hopefully very noisy," he added. "Hopefully with the news that has come out in the last few weeks that things are looking up.
"We are really looking forward to getting back and competing in Scotland, great experiences in the past representing Britain in the Davis Cup.
"For me I know the players, I know how competitive they are and if you put them all together they all want to beat each other and I knew they would go hell for leather to try and win and that really shone through and that is why people enjoyed watching it, it was real.
"Either of those events in normal times would sell tickets and be a lot of fun to be involved in."