Former Sevilla left-back Moreno has had an interesting start to the season following his £12 million to Anfield.
On his second official game with the Reds, the 22-year-old scored what he described as his best goal in ever in the 3-0 rout over Tottenham Hotspur.
Moreno’s form though has dipped since then and a niggling injury ruled him out of the Spanish U21’s 1-1 draw with Austria in September.
Nevertheless, Spain U21 boss Albert Celades felt the need to bring him back into the squad and also opted for another Liverpool new-boy Javier Manquillo.
The Atletico Madrid loanee has been heavily involved in Brendan Rodgers’ side at right-back and has proven to be adequate competition for England international Glen Johnson.
Manquillo, 20, has only ever featured once for his country at U21 level and he will be hoping his strong start to life in the Premier League will see him given more recognition.
Reigning European champions Spain take on Serbia at the Gradski stadium in Jagodina on Friday 10 October in the first leg of the European Championship Playoffs .
The return leg is programmed for four days later at the Ramón de Carranza in Cádiz, a game the Spaniards will be hoping to celebrate as they bid to reach next year’s major tournament in Czech Republic.