Gareth Southgate's men have won just one of their last five matches - a run that includes a 1-1 draw with North Macedonia and a shock 1-0 home defeat to Iceland in their final warm-up match before flying out to Germany.
England are still expected to cruise through a group that also includes Denmark and Slovenia.
However, a dominant display is required against the Serbs in Gelsenkirchen to settle nerves at the start of another tournament filled with high expectations, but which could still fail to deliver a long-awaited trophy.
Defensive crisis
The biggest question over England's credentials to be European champions is at the back as injury has robbed Southgate of his settled back four from previous tournaments.
Harry Maguire failed to make the squad due to a calf problem, while Luke Shaw is included as the only natural left-back despite not having played any minutes for club or country since February.
John Stones is therefore even more crucial as the one experienced centre-back at international tournament level, but the Manchester City man has also been dogged by fitness problems this season.
Kieran Trippier, a right-back by trade, is set to start against Serbia at left-back.
Crystal Palace's Marc Guehi is the leading candidate to partner Stones for his first major tournament start.
England's defensive deficiencies have already been exploited by Brazil, Belgium and Iceland in 2024.
And Serbia have the firepower to hurt them with their powerful strike pairing of Aleksandar Mitrovic and Dusan Vlahovic.
Attacking balance
Southgate's paucity of options at the back are compensated by the abundance of weapons in attack.
"England's front six is one of the best if not the best in world football," said former England captain Alan Shearer.
"The players, the talent we have will be a threat for anyone in world football."
Marcus Rashford, Jack Grealish and James Maddison failed to even make the 26-man squad.
The quartet of Phil Foden, Jude Bellingham, Bukayo Saka and Harry Kane is the envy of Europe.
However, Southgate is still to find the right balance to help them perform on the international stage to the same level as they have for their clubs this season - the quartet scored a combined 114 goals in club football in the 2023/24 campaign.
Foden won Premier League player of the year accolades this season from a central role but has been shunted out left to accommodate Bellingham as a number 10.
Southgate has so far been reticent to play both in the middle either side of Arsenal's Declan Rice with Chelsea's Conor Gallagher or Trent Alexander-Arnold, who normally operates at right-back for Liverpool, instead set to start in central midfield.
'Last chance' for Southgate
Southgate's tenure has catapulted England back into contention for major honours.
There is plenty to laud from his record of a final, semi-final and quarter-final from three major tournaments.
However, there are still many in his homeland that doubt his killer instinct to be able to get over the line when it counts.
England were guilty of throwing away early leads in the Euro 2020 final against Italy on home soil and in the 2018 World Cup semi-final when up against a jaded Croatia.
"If we don't win, I probably won't be here anymore. It might be the last chance," Southgate told German publication Bild this week.
Southgate's contract is set to expire at the end of the year, and he is all too aware that the blessing of having such a richly-talented squad to choose from also means there will be little allowances made for failing to come home with the trophy this time.