Iraola heads to Merseyside on the back of three superb campaigns at Bournemouth, including a first-ever European qualification at the end of 2025/26, and Alonso also returns to English football after an ill-fated spell at Real Madrid.
One manager who knows both clubs well - and the challenges as a Spanish coach in the Premier League is Rafa Benitez - who famously led Liverpool to the UEFA Champions League title in 2005 and won the 2013 Europa League at Chelsea.
The veteran coach is confident both Iraola and Alonso will excel in the coming months but he believes the former has a key advantage over his Basque compatriot.
"Iraola has done really well at Bournemouth. I followed him during his time at Rayo Vallecano and was impressed. Now he has a different challenge at Liverpool," he told Sky Sports.
"Liverpool is a massive club. But, I think he has an advantage as he knows the league. It's not easy to arrive new to the Premier League from other countries.
"Xabi is a very clever coach. He did very well with Leverkusen, that was fantastic. We know from experience that it's quite complicated to manage Real Madrid. He has knowledge of the Premier League as a player, but this is his first time managing here.
"That will be a challenge, but he has h skills to do well."