You hope to bring your 'A Game' to any game, and of course you do in a final. You hope to bring experience, fitness, communication skills, motivational skills.
I went to Fulham for the project they explained to me - but it didn't really work out. I might have been playing at a high level for the national team, but I was starting to miss those European nights and challenging for titles.
Running a marathon is unlike anything I have done. You can recall all those bad weights sessions or the work you had to do in pre-season, but marathon running is worse than any of it, probably the hardest thing I have had to do in my entire life.
You don't need only your strikers. You need your defenders to be on top of their game. You need a midfield to work hard and track back, and I suppose you need a goalkeeper who makes saves once in a while.