Leicester City defender Cian Bolger has returned to Bristol Rovers for a third time, on loan until January.
Bolger, 20, has made a total of 48 appearances for Rovers over the past two seasons.
The Republic of Ireland Under-19 international has yet to feature for his parent club.
"Cian's arrival also gives us a flexibility in that it will enable us to play different systems," manager Mark McGhee told the club website.
"We have four central defenders, all of whom are comfortable with whatever system we choose to go with, and now we have cover for places at the back.
"It really is good to have Cian back with us and he will go straight into the squad for tomorrow's game against Morecambe."