The fixture is one of the most fiercely contested in the English football calendar, with the 34-year-old claiming that it is always eagerly awaited as the biggest game of the season for the Reds.
Speaking to Liverpool's official website, Alonso said: "I look out for most of the games. But this one especially because of how big it is, the build-up and what it means for both clubs to be successful after 90 minutes, to be the winners.
"Liverpool against Manchester United was our big game of the season, whenever they were coming to Anfield or whenever we had to go to Old Trafford, because the tension between the two crowds was so strong you could feel it on the pitch.
"These kinds of games, anyone can win. Maybe Liverpool are in a better position and maybe favourites, but it doesn't matter. United still have great players and a good team. This game is so important for them because they don't want the gap to be bigger."
Alonso, now with Bundesliga champions Bayern Munich, played for Liverpool between 2004 and 2009, winning the Champions League and FA Cup during his time at the club.