How do I play my first game against the u-21 team?

Hey

I just bought the game - I've set up my team, tactics and etc. and I can't play the first game. Apparently my first team members are in the u-21 team as well? I'm playing with Arsenal and even players like Sanchez, who are well into their 20's, are on the list. What the hell is going on? How do I take them out that u-21 team?

When you click on squad you can select Senior Squad, U-20, U-18 etc... if you're seeing all of them in one squad then click on the show filters button and untick the youth teams out of your senior squad.

I did so and the problem still occurs. My first team players apparently are in "the opposite team"? How do I move them out of that team? This is getting really annoying.

Can you maybe post a screenshot of what you mean? The pic will need to be uploaded elsewhere (imgur etc) and paste the link here.

It sounds like you made them available for the other teams to use though. Before every U20/U18 match you will be asked, in a news item, who to make available. Otherwise, right click on the affected player, go to Squad and find the option that's selected in the 'Available For....' options. You'll know if it is selected, because there will be a bullet point next to the option. Just select the option again to remove the availability.