Eriksson immediately replaced Vassell with Leeds United striker Fowler, who was desperate for action after recovering from a hip injury.
And he almost announced his arrival with an immediate goal - but he was inches away from a decisive touch when Teddy Sheringham headed Sinclair's excellent cross across the face of goal.
Fowler had better luck with a close-range header in the dying seconds - again from a Sheringham header - to at least save England from the disappointment of defeat.
England: Martyn (James 46), Brown, Ferdinand (Keown 46),
Campbell (Southgate 46), Bridge, Hargreaves,
Scholes (Mills 46), Joe Cole, Heskey (Sinclair 46),
Vassell (Fowler 76), Owen (Sheringham 46).
Cameroon: Alioum (Songo'o 78), Song (Ndo 69),
Kalla (Mettomo 56), Tchato, Geremi (Alnoudji 66),
Wome (Njanka 61), Lauren (Suffo 60), Foe (Djemba-Djemba 53),
Olembe (Kome 53), Eto'o (Epalle 60), Mboma (N'Diefi 66).
Subs Not Used: Job, Kameni, N'kom.
Referee: Y Katayama (Japan)