Tremmel, a former Bayern Munich youngster, has joined the squad at the training camp in Austria and will attempt to persuade Brendan Rodgers into offering him a contract.
The 32 year old left Red Salzburg earlier in the summer, so is a free agent.
He featured in Salzburg's Europa League campaign last season, starting against the likes of Manchester City and Juventus.
Swansea are keen to land a number one stopper before the Premier League kicks off in 14 days time.
This article first appeared on JACKARMY.net.