The leg-spinner is due at Gatwick for a mid-evening check-in, up to four hours' drive from Leeds, but Kent officials were hoping to find a later departure time.
Leaders Kent, 18 points ahead of third-placed Yorkshire, have only Nigel Llong's off-spin as an alternative. Llong has four championship wickets this year, Strang 58.
Yorkshire have continuing doubts over Darren Gough's fitness. Their main seam bowling could be carried by Chris Silverwood and Paul Hutchison, both selected for England's A tour yesterday.
County Ch'ship (1st day of 4: 10.30am start): Chester-le-Street: Durham v Somerset. Cardiff: Glamorgan v Essex. Southampton: Hants v Sussex. Lord's: Middx v Notts. Northampton: Northants v Leics. The Oval: Surrey v Lancs. Edgbaston: Warwicks v Gloucs. Worcester: Worcs v Derbys. Headingley: Yorks v Kent.
2nd Xi Ch'ship (2nd day of 4): Bristol: Gloucs v Worcs. (1st day of 3): Chelmsford: Essex v Derbys. Bournemouth Spts Club: Hants v Kent. Old Trafford: Lancs v Surrey. Trent Bridge: Notts v Sussex. Taunton: Somerset v Middx. Kenilworth Wardens: Warwicks v Northants.