But Vertonghen's side can go into the match with great confidence. They have won five of their six group matches so far, including an impressive 3-0 away win against Friday's opponents back in October.
"The qualifier against Serbia is very important. We’re top of the group now, level on points with Croatia and we want to stay there and go directly to Brazil," Jan told tottenhamhotspur.com.
"I’ve never been to a World Cup or European Championship and I think Belgium is ready for it. We have a good team, good players and the pressure is there now.
"Everyone is ready. We have the group to qualify and to get to Brazil would be amazing."
His country face a vital World Cup qualifier against Serbia in Brussels on Friday night and with the top spot in Group A still up for grabs - Belgium are currently level in first place with Croatia on 16 points - each game takes on an increased level of importance.