The former Germany and Bayern Munich goalgetter says Gomez, Klose, Bayern Munich's Lukas Podolski and Kevin Kuranyi of Schalke 04 are the country's leading strikers.
"Klose is the best and most important of the four. Gomez is second best, he's always there. These two will be the number one (strikers) at the European Championships," said Mueller, whose 68 goals for Germany is a record.
Kuranyi has established himself in the national side following the 2006 World Cup, but is currently injured.
Coach Joachim Loew has also kept faith with Podolski although he has spent most of the time this season on the substitutes' bench at Bayern.
Loew has called up Hanover's Mike Hanke and 34-year-old Oliver Neuville of Borussia Moenchengladbach into the Germany squad for forthcoming Euro 2008 qualifiers against Cyprus and Wales.
Stefan Kiessling of Bayer Leverkusen, Gerald Asamoah of Schalke and Patrick Helmes of second-division Cologne are also candidates although none of them are in the current squad.
Gomez, 22, only made his debut in the national team in February, and has scored three goals in five appearances.
The son of a Spanish father and German mother, he was voted German Football of the Year after scoring 14 goals in 25 games last season in VfB Stuttgart's league title triumph.