The former paramedic, who was originally signed by Merrick as a back-up squad player, was a vital screen in front of the defence as well as an impeccable distributor, hardly ever caught in possession.
Riera impressed to such a degree he was named in the A-League All-Stars team to face Juventus in August 2014, marking one of his idols Andrea Pirlo and on the pitch alongside other luminaries such as Carlos Tevez and Paul Pogba. He was one of only three on the invitational team to complete the 90 minutes.
Riera was hampered by some persistent injuries last season but still one of the most consistent at the Phoenix. Hence the genuine surprise when he informed coach Merrick after the final match against Western Sydney Wanderers last season that he no longer had the appetite for full time football.
"It was a very hard decision to make but I had been thinking about it for seven months," said Riera at the time.
"My time at the Phoenix has been the highlight of my life; a fairy tale that it was hard to believe was happening.
"[But] I've had a few injuries lately and as you get older it becomes harder to shake them off. It has nothing to do with money; it is a very personal thing and it was difficult to tell Ernie what I wanted to do."
At the time, Merrick tried to dissuade Riera from his decision and admitted that signing Riera - after seeing him a friendly match against Auckland City at Kiwitea Street in September 2013 - was "one of my best decisions in football".
But the Spaniard was adamant, deciding he needed a physical and mental break from the rigours of professional football, with the regular transtasman travel and extensive training load.
Riera played 68 games for the Phoenix across three seasons between 2013 and 2016.
His return to Auckland City is a considerable coup for the local club as he was one of the most dominant players on the domestic scene between 2011 and 2013, and was named in the inaugural ASB Premiership team of the decade in 2014.
