Robson has had just two competitive games since becoming Thailand's coach in October and could be left with only minor regional tournaments and one-off friendlies if his side fail to beat Jordan in Bangkok on Wednesday.
The former England skipper says Thailand, heavy favourites for Wednesday's game, are too good to miss out and believes his players will prevail in a tight group that includes arch rivals Singapore and three-times Asian champions Iran.
"It is a must-win game, but the pressure's not on us any more than the other three teams," Robson told Reuters.
"It's exciting, but we really didn't want it to be this exciting. We've slipped up, but the players know how important this game is and they've been working really hard."
Iran lead Group E on seven points, trailed by Singapore (6), Thailand (5) and Jordan (4). All teams have two games remaining and the top two will reach the tournament in Qatar in January next year.
Qualification for Qatar will be all the more important after Thailand were embarrassingly dumped out in the group stage of last month's Southeast Asian Games, a tournament of huge importance to Thai fans who reacted angrily to the early exit.
If Robson's team miss out on the Asian Cup finals, they face a wait of nearly two years for their next big contest, which will be Asian qualification for the 2014 World Cup in Brazil.
Wednesday's match will be the biggest test so far for Robson in his first international coaching post, a job he said he was enjoying but sometimes found "a little frustrating".
If Thailand fail to beat Jordan, they may require an unlikely victory in their final match against regional giants Iran in March. However, Robson says his new team can beat the Iranians, even at Tehran's notoriously hostile Azadi Stadium.
"For me, what I've seen of Iran there's no reason why we shouldn't go there and get a good result," he said.
"The players know it's still there for them to qualify and they're up for this challenge. They've done very well so far and I'm quite impressed with them."
