Rangers have given former German international David Odonkor a trial at the club.
The 27-year-old winger is a free agent, having ended his contract with Spanish side Real Betis.
Odonkor began his career at Borussia Dortmund before making the switch to La Liga. However, continuing injury problems limited him to only 51 appearances in five years for the Spanish club.
The Gers have already made three signings this summer with Juan Manuel Ortiz, Lee Wallace and Dorin Goian all making the move to Ibrox.