Buttler, who has seven ODI centuries to him name, including his electrifying 77-ball 150 against the West Indies last month, is in the form of his life now.
And Trescothick, who played with Buttler at Somerset earlier in his career, believes the big-hitter holds the key to England ending 44 years of hurt and finally win the World Cup this summer on home soil.
“That hundred he scored against the West Indies was absolutely sensational. To see someone, play in that fashion is quite stunning,” said Trescothick, who was helping to launch the 'Wickets' mural in Taunton, which gives fans a chance to win a pair of tickets to CWC19.
“Jos is on fire and whatever game he is playing and in whatever format, he is superb now.
“I really hope his form continues into the World Cup, because if he is in form then he will be the stand-out difference for England.”
Having reached the World Cup Final on three previous occasions - in 1979, 1987 and 1992 - Trescothick believes England’s time is now and they will finally get their hands on the biggest prize in limited-overs cricket.
The former England opener says that the tournament being played on home soil cannot be underestimated and is an advantage for Morgan’s men.
“I think it will come down to two teams, either England or India to win it," he added.
“They are ranked one and two in the world and I think England has as good a chance as we have ever had to win the World Cup with the home advantage.
“It is a big deal to play World Cup matches at home. Having experienced one World Cup in my career back in 2003, it would have been lovely to have it in your own country.
“It is homelier, and there is a chance to get away from it and you are secure in your surroundings, you know the hotels and the places you go to in each city, you know all the grounds. It is all more familiar and a bit more relaxing.
“There are other demands. The crowds will expect, and the country will put a bit of pressure on the team, but they are in such a good place now that I believe they can cope with those things.”