ALL players you acquire will be starting from square one at the Bronze tier, so it’s up to you to make them better!

Players on your roster can be improved with a combination of both currency and XP.

XP is collected when trading in unwanted players from your inactive roster or when
obtaining a player you already have on your roster.

When a player reaches level 10 at his current tier, he cannot be promoted to the next tier unless your team is at the appropriate tier.