By John Irish

MARSEILLE, France (Reuters) - When France meet Portugal in Sunday's Euro 2016 final, the outcome is likely to depend on the performances of Cristiano Ronaldo and Antoine Griezmann -- the second time the two players have clashed with a European trophy at stake in six weeks.

Portugal's Ronaldo steered Real Madrid to their Champions League triumph at the end of May after his French rival Griezmann missed a penalty for city rivals Atletico.

The France striker has certainly bounced back from that disappointment. He is the competition's top scorer with six goals, having scored both goals in Thursday's defeat of world champions Germany.

Portugal's master tactician Fernando Santos needs to cut supply lines to a player whom the French call "Monsieur Griezmann" as a sign of respect -- despite his boyish looks.

It will be a challenge.

While Portugal saw off Wales, the Welsh playmaker Gareth Bale was still given enough space to create chances and were outdone more by the absence of midfield creativity than by Portuguese prowess.

That will not be the case for France who have a larger arsenal. Even if Portugal can snuff out Griezmann, Dmitiri Payet, the stand-out performer in the earlier rounds, can change a game in seconds.

Front man Olivier Giroud has also proved a handful by weighing on defenses and making space for those around him.

TEAM SPIRIT

What has worked for Portugal has been an incredible team spirit with a mantra that they are not playing to look pretty, but to win, irrespective of style.

Santos has fashioned a well-drilled 4-4-2 and kept to it throughout despite injuries. The loss of Pepe at the back was hardly noticeable against Wales with Bruno Alves stepping in admirably.

From France's match with Germany, Santos will have noted that Didier Deschamps' team has a weakness on its flanks, in particular on the left with Patrice Evra.

The Germans pushed the French very deep by using their full backs almost as wingers. For much of the match, France's midfield duo of Paul Pogba and Blaise Matudi chased shadows, leaving Joshua Kimmich and Jonas Hector with acres of space.

Portugal's full backs Raphael Guerreiro and Cedric Soares are good enough to replicate that, which could push Deschamps to move away from the more attacking 4-2-3-1 formation to revert to a 4-3-3, restoring defensive midfielder N'Golo Kante.

But whether the Portuguese midfield has the capacity of a Bastian Schweinsteiger or Toni Kroos to stifle France is questionable.

NO DEPENDENCY ON RONALDO

Danilo, who replaced William Carvalho against Wales, was strong and efficient in the holding midfield role, but has limits going forward.

Joao Mario and Adrien Silva do not appear to have the killer pass for Ronaldo or strike partner Nani. That may open the door for playmaker Joao Moutinho to return.

What has been evident with this Portugal side is that they are no longer a side entirely dependent on Ronaldo. On the contrary, when he goes missing, others shine.

In the quarter-final against Poland, 18-year-old Renato Sanches took the plaudits, while Nani has netted three times.

Portugal's most high-profile player may have three goals, but his Real Madrid explosiveness has been absent. He has had to fit into Santos' team ethos, playing a less glamorous role. Captain Ronaldo tracks back and encourages his teammates.

Arguably by being quiet he may prove more lethal. France's defenders can not fall into the sleepy rhythm Portugal have set during the tournament because Ronaldo has enough to turn the tide as his majestic header against Wales showed.

(Reporting By John Irish. Editing by Adrian Warner.)