Lonergan, 35, joined the Reds for their pre-season tour of America after a goalkeeper shortage left them with only Simon Mignolet and inexperienced Dan Atherton as an option between the sticks and has been training in Melwood ever since.
He is now expected to be on the bench for the European Super cup final but what do we know about the new Reds keeper?
Born in Preston he joined Blackburn Rovers youth academy after they beat of the likes of Everton & Manchester United to his signature, it would be a short stay for Lonergan who would later join his hometown club Preston North End and made his debut as a 16 year old in a league cup game against Coventry City.
He would go on to represent the Republic of Ireland u16 team and win the Preston young player of the year award on his debut season, during the next couple of seasons he would bounce around between league clubs on loan acting as a number two and had switched his international allegiance to England, representing their u20 side ten times.
In 2004 he became the Preston number one and most notably scored a goal in a Championship game versus Leicester City, Lonergan would go on to make over 200 appearances for his home town club before again shunning a move to Everton in favour of moving to Leeds United.
It was a frustrating season for the player who was in and out of the team due to niggling injuries but still managed 35 appearances that season, but after losing his first team spot he moved on to Bolton Wanderers where he competed with ex Red Adam Bogdan for the number one spot.
Again injury hampered his stay at Bolton and he was rotated with Bogdan as the clubs number one making just a total of 51 appearances in three seasons before moving on to Championship club Fulham where he would be the number one for the majority of the season being one of their most consistent performers.
The next three season for the keeper would see him going from Wolves, Leeds United again and Rochdale where he acted as a backup keeper and his appearances became limited.