Ronny Rosenthal and four more unusual LFC loan deals

Almost three decades later, he would play a crucial role in helping Liverpool win the 1989-90 championship and gain cult status on the Kop following an ebullient start to his Reds career.

Signed on loan from Belgian club Standard Liege in March 1990, 'Rocket Ronny' scored seven goals in eight games during the season run-in to help Kenny Dalglish's side win back the title from Arsenal.

He had arrived at Anfield as a back-up option to the established forward line of Ian Rush, Peter Beardsley and John Barnes, but a perfect hat-trick on his full debut - a 4-0 win at Charlton Athletic - saw him become an instant hit with the fans and earn the trust of his manager.

The transfer was made permanent at the end of the season and he would go on to play 97 games during three years with Liverpool, including a memorable appearance in the Merseyside derby at Anfield in 1993 when he scored an injury-time winner against Everton.

His initial loan was a rare thing for the club back then - so, to mark Ronny's 55th birthday we've picked out four other unusual temporary deals from recent history...

Paul Jones

International goalkeeper Paul Jones earned a half-century of caps for Wales and played almost 200 games for Southampton, but few people ever expected to see the veteran stopper pull on a Liverpool shirt.

However, in January 2004, with Chris Kirkland nursing a broken finger and Jerzy Dudek suffering a groin injury in a midweek clash with Chelsea, manager Gerard Houllier moved to sign him on an emergency month-long loan.

"Whether I play one game, two games or whatever, I am just relishing the chance to play a part," Jones said after arriving at Anfield. "I've been a Liverpool fan all my life so to be here really is a dream for me."

Jones made his bow the next day, keeping a clean sheet in a 1-0 win over Aston Villa, and entered into the LFC record books as the oldest post-war debutant: three months shy of his 37th birthday.

In his second, and final, game against Tottenham Hotspur he beat Bruce Grobbelaar's record as the club's most senior goalkeeper by 138 days.

Ian Rush

In the summer of 1986, after winning 10 major trophies and the European Golden Boot with Liverpool, Ian Rush agreed a deal to join Italian giants Juventus.

But there was a snag.

The Serie A side already had Danish international Michael Laudrup and French superstar Michel Platini on their books, meaning Rush wouldn't be able to play for the Old Lady due to the 'two foreigner' rule.

Juve president Giampiero Boniperti offered a solution, as Rush recounted in his autobiography.

"We will sign you now and loan you out to Lazio [in Serie B] for the season, then when Platini retires, you come back here," he wrote.

"'With all due respect, no,' I said. 

"'OK, if I have to go on loan, what about this,' I suggested. 'I sign for Juventus and I go back to Liverpool on loan for the season.'

"The lawyer raised his eyebrows, but I could tell by the slight sideways nod of his head he thought this a possible solution to the impasse."

The deal, as unusual as it was at the time, went through. Rush stayed for another season and scored an incredible 40 goals - the second-highest tally of his career - across all competitions.

He joined up with Juve for the 1987-88 campaign but stayed in Italy for just that one season. The Welshman re-signed for Liverpool in August 1988 and went on to become the club's record goalscorer.

Javier Mascherano

In the summer of 2006, with a host of top European clubs tracking Argentina international Javier Mascherano, he and his Corinthians teammate Carlos Tevez signed for West Ham United.

If the transfer itself caught many by surprise, it was even more astonishing to see Mascherano - a title-winner in Argentina and Brazil - regularly excluded from a Hammers side struggling at the wrong end of the table. 

Less surprising, however, was a January bid from astute Reds boss Rafael Benitez to sign the highly-rated midfielder on loan. It was a switch that appeared to suit all parties, but there were issues. 

Mascherano had played for both West Ham and Corinthians in 2006 and could not play for a third club in the same campaign; FIFA ruled the English and Brazilian seasons didn't overlap and approved the deal on deadline day.

However, the Premier League wanted more time to deliberate and it wasn't until 20 days later that they gave Liverpool the thumbs-up. Benitez's new man went straight into the team and helped the Reds reach the 2007 Champions League final.

A permanent deal followed in 2008 and Mascherano went on to establish himself as one of the world's best defensive midfielders during three-and-a-half years at Anfield.

Steven Caulker

In January 2016, Liverpool signed Queens Park Rangers centre-back Steven Caulker on a short-term loan to ease a defensive injury crisis that had claimed Dejan Lovren, Martin Skrtel, Kolo Toure and Mamadou Sakho.

Reds boss Jürgen Klopp was eager to provide an aerial presence in his depleted defence and determined that the 6'3" former Tottenham player was the 'best solution'.

However, when the one-time England international made his debut the following day, it was as an emergency striker, not a defender.

With Klopp's side 3-2 down against Arsenal, the nominal centre-back was thrown up front to replace Adam Lallana just before Joe Allen grabbed a last-minute equaliser.

In fact, three of Caulker's four appearances for the Reds came as a substitute striker. 

It was his persistence in the box that led to Lallana's dramatic last-gasp strike that secured a thrilling 5-4 win at Norwich City and sparked celebrations that ended with Klopp breaking his glasses.