ARAM Summoner Spells On Twisted Treeline

I played a game of ARAM before accidentally queuing for a game of twisted treeline. While I was hovering over champions and wanted to change my spell to smite, it was no there. Instead, it seemed to be showing me the summoners spells from ARAM. I haven't played Twisted Treeline in years, but the 2 people I was matched with said it should be available. In the end one of the other guys had to jungle because smite wouldn't show up for me.