The gist: open the player pool, claim a guy so no one else calls him, then roster him to put him on the lineup card (and return him after if he was just filling in).
Tap your personal link
The commissioner texts you your team's player-pool link. It's also at the bottom of every lineup email. Tap it and the pool opens, already signed in as your team — bookmark it.
See who's available
Available players are listed first — name, contact, and their position, age, and experience. Players other managers have already claimed show lower down, labeled with who's got them.
Claim him before you call
Tap Claim to put a soft hold on a player while you phone or text him. Other managers now see “Claimed by you” — so nobody double-calls the same guy.
He's playing? Add to your roster
Once he says yes, tap Add to roster and confirm. That's what puts him on your team's lineup card for the game and takes him out of the pool. He only ever joins your team, and you can't roster anyone another team has claimed.
Fill-in or full-time? Roster a fill-in the same way — a guy trying out or visiting town — then return him to the pool after the game (next step). If he's actually joining your team, just leave him rostered.
He'll move onto your roster and out of the pool.
Fill-in done? Return him to the pool
The Rostered by you section lists everyone you've added. Tap Return to pool to send a guy back — whether he was a one-game fill-in, a tryout that didn't stick, or just a wrong tap. He's right back for other managers.
A few days before each game you'll get a lineup summary — who's in, maybe, out, and who hasn't answered — with a heads-up if you're short and a link straight to the pool.