On 5 December, Niculae scored his first brace for Romania in a 2–3 defeat against Algeria. Three days later, he scored another brace against the same opponent. On 24 March 2001, Niculae played his first qualifying match for Romania, in a 0–2 defeat against Italy. On 2 June, he scored another brace for Romania against Hungary. He scored his tenth international goal on 10 November in a 2002 World Cup Play-off, where Romania lost 1–2 against Slovenia. Romania failed to qualify to the 2002 World Cup, since they managed only a draw in the second leg. On 20 August 2002, Niculae was recalled for Romania, ending a nine-month absence caused by a long-term injury.