From the bizarre to the brilliant, the Black Cats have brought a number of players into the Academy of Light on a temporary basis over the last few years.
We’ve rounded-up some of the more forgettable and fascinating names, but how many can you remember? Scroll down and click through the pages – and let us know if you saw any in action:
13. Bolo Zenden
Arguably the player on this list who made the biggest impact, Zenden joined Sunderland on trial before impressing enough to win a deal. He went on to spend two seasons on Wearside and quickly became a fans' favourite. Photo: Mike Hewitt
14. Joleon Lescott
The less said about Lescott's time at Sunderland the better - but he obviously impressed David Moyes enough during a trial to win a short-term deal with the club. Photo: Laurence Griffiths
15. Robbin Ruiter
One of the more impressive trialists in recent years, Ruiter ended up with a two-year deal at Sunderland. He was released last summer and subsequently joined PSV Eindhoven in his native Holland. Photo: Nigel Roddis
16. Kacper Przybylko
The Polish striker, formerly of Cologne, spent time with Sunderland in 2018 but didn't stay beyond his trial spell - instead heading to the MLS and joining Philadelphia Union. Photo: DANIEL ROLAND