Perpignan back Hook underwent a medical review of his recent bout of chicken pox at the Wales team headquarters in London after flying in from the French-based club this afternoon (Thursday).
Although Hook is physically well it was felt that, in the best interests of the Welsh team and the opposition, he should be withdrawn from the game.
Whilst this decision has not been taken lightly, it was concluded that this was the most responsible course of action in the present circumstances.
Jones, who holds the Welsh records for the highest number of international appearances (104) and most conversions (153), will wear the number 21 shirt vacated by Hook.
Jones made his international debut as a replacement against South Africa in 1998 and is a veteran of two Welsh Grand Slams (05, 08), four Rugby World Cups (99, 03, 07, 11) and two British and Irish Lions Tours (05, 09).
Stephen JONES (SCARLETS - Cap No 966)
DoB: 08.12.77. 6'1" / 1.86m. 14st 7lbs / 92kgs
International record: 104 caps (W 42, L 58, D 3; 917 pts - 7T, 153C, 186PG, 6DG)