#2 Iker Casillas (FC Porto)
If the offer for Allison is not successful, Liverpool may choose to bid for a very experienced goalkeeper, Spain's Iker Casillas.The goalie has been playing for FC Porto since leaving Real Madrid in 2015 and would likely be interested in a move to the Premier League, considering Liverpool's rise in form especially.
At 36, there are few players with a higher level of experience. Casillas possesses great reflexes and concentration, aswell as impressive leadership skills. Making good use of these qualities, the Spaniard became one of the most successful players in the modern era.
The keeper has won the Champions League trophy on three occasions with Real Madrid. He has is also a World Cup and a European Cup winner (twice) with Spain. Liverpool would certainly benefit from his illustrious past and his desire to prove himself by taking on a new challenge in the twilight of his career.
There is some uncertainty at the moment regarding Liverpool's current goalies. Simon Mignolet is expected to leave the club in the summer, with Loris Karius yet to fully convince Klopp due to his inconsistent form. Above all, transferring Iker Casillas would prove to be a signal of intent by Liverpool.