The 32-year-old German has been on trial with the Swans after leaving Red Bull Salzburg at the end of last season. He impressed in the pre-season friendly victories over Celtic and Real Betis and has been handed a two-year contract by the south Wales club. Tremmel told the club website: "I am delighted to be here as a Swansea player. "I've been with the club for quite a while on trial, and I already felt part of the squad as everyone here is so welcoming. It is a family club. "I have also had the chance to see how the team gets on in the Premier League, and I have been impressed by what I have seen."