Isle of Man TT organisers the ACU has confirmed race week could be shortened to four days and begin on Tuesday, should poor weather continue to cancel practice sessions.
Four qualifying practices have been lost to bad weather on the Island so far this week, with Thursday afternoon's scheduled combined Superbike/Superstock/Supersport/Newcomers outing and the Sidecar session the latest to be scrapped.
The ACU is still hoping a break in the weather will allow the evening schedule to run, but contingency plans have already been put in place to expand practice week should any more sessions be lost.
On Wednesday, Clerk of the Course Gary Thompson confirmed Saturday's opening race day could be pushed back to Sunday to allow qualifying on Saturday.
If no more running is held prior to the weekend, Thompson admitted another practice could be staged on Monday next week and begin four-successive days of racing from Tuesday through to Friday.
"If we don't get anything in between now and the weekend, we could well be looking at Monday as a qualifier and squeeze the race days in Tuesday through to Friday," Thompson told Manx radio.
"The race authorisation is pretty flexible. I have got quite a bit of flexibility there, so the worst-case scenario is that we may have to use Monday as a qualifier - if we don't get anything in between now and the weekend - and have races every day next week from Tuesday through to Friday.
"We'll get them in, we have done before and we'll do it again."
The current race week schedule has racing beginning on Saturday June 1, with Monday, Wednesday and Friday completing the schedule.
Most of the solo riders have only had two sessions so far.
But outright lap record holder Peter Hickman has had just one and only on his SSP bike due to technical issues with his SBK and STK BMWs.
Hickman missed the opening day due to his commitments in the British Superbike Championship.
Aside from the newcomers in the class, the Sidecars have also only had one outing, with most only completing a single lap on Tuesday night.
Thursday's session is due to begin at 6.20pm local time with the SBK/STK/SSP/Newcomers session, followed by a combined SSP/Lightweight qualifying at 7.15pm, an outing for the Sidecars at 7.55pm and a session for the electric Zero bikes at 8.40pm.