MELBOURNE, March 31 (Reuters) - Australia's friendly wins over ⁠Cameroon and Curacao were a boost before they head overseas to continue their World Cup buildup but the matches also left nagging questions ⁠about the Socceroos' squad depth.

Australia wrapped up the FIFA Series with a welcome glut of goals in a 5-1 rout of Curacao ‌in Melbourne on Tuesday, which followed a lacklustre 1-0 win over Cameroon in Sydney last week.

Coach Tony Popovic gave debuts to forward Deni Juric and teen defender Lucas Herrington against Cameroon while trying new combinations up and down the field in both the home fixtures.

Popovic declared it "mission accomplished" after getting wins and a good look at new players but the experiments largely fell flat ​against the lower-ranked teams.

The Socceroos struggled with their much-changed lineups in both matches and relied on ⁠first-choice players coming off the bench to turn the tide ⁠in their favour.

Herrington was praised for a composed debut in the stodgy win over Cameroon but the 18-year-old's lack of experience showed during the first ⁠half ‌against Curacao.

Juric had a shaky debut against Cameroon and he may not have done enough against Curacao to convince Popovic he is worth a place in the World Cup squad.