Preston have taken Gabor Gyepes and Goran Lovre on short-term trials.
Hungary international Gyepes was released by Cardiff in February after four-and-a-half seasons with the npower Championship club.The 30-year-old centre-back previously played for Wolves and Northampton in English football.
Ex-Barnsley midfielder Lovre, 29, has also been without a club for the past month following his release from Oakwell.
Lovre, a former Serbia Under-21 international, began his senior career in Belgium with Anderlecht before moving to Dutch outfit FC Groningen.
"The two lads are on short-term trials and that is about a manager taking a look at players who want to be part of the future," North End manager Graham Westley told the club's official website.
"You have to be prepared to be ready to assess them. You have done your initial work to give you reasons why you are willing to take a look at them."