I think a big part of teamwork is filling the needed role. Calling asap is done by desperate people who are very limited at what they can do. Instead I reccomend learning how to play all 4 lanes (Top, Mid, Bot, Jungle) and all 6 roles (Solo top AD or AP, Solo mid AD or AP, ADC, Support, Jungling, Bot Kill lane support). At champion select I say "any lane, any role" and it makes my team happy every time. For advice on what champs to learn so you too are able to do this I will gladly share. Udyr, Reneckton, Sona, Teemo, Vlad, Soraka, Graves. I can play these champs in any lane in any role including jungle.