But the Australian coach could take plenty of encouragement from a 3-1 victory over Sheffield Wednesday at Dragon Park in Newport on Wednesday afternoon as several of his club’s academy products suggested they could force their way into his longer term plans.
In a match played over three periods of 30 minutes, Celtic recovered from a sluggish start which saw former Rangers forward Josh Windass give Sheffield Wednesday a third minute lead.
The response could only have been pleasing for Postecoglou as goals from Albian Ajeti, Owen Moffat and Odsonne Edouard secured the win.
The sight of last season’s top scorer Edouard getting on target in typically accomplished fashion was perhaps the most pleasing aspect for Celtic supporters. Speculation continues to surround the future of the gifted French striker as he enters the final year of his contract but his presence will be vital if Celtic are to progress through a Champions League campaign which kicks off with the first leg of their second qualifying round tie at home to Danish side Midtjylland on July 20.
Of the raft of younger players Postecoglou involved against Wednesday, 19-year-old winger Moffat made the biggest impression. Pacy, direct and technically sound, Moffat was handed a contract until 2024 earlier this year and it’s easy to see why Celtic rate him so highly.
Dane Murray, an imposing 18-year-old central defender, also caught the eye and was the only Celtic player to complete the full 90 minutes against their English League One opponents.
Celtic were caught cold by Wednesday’s faster start to the match, Ismaila Soro giving the ball away cheaply to allow Scotland internationals Barry Bannan and Liam Palmer to combine and set up Windass for a neat finish beyond goalkeeper Vasilis Barkas.
It took a while for Celtic to settle into the high tempo which Postecoglou has made clear he will demand of them. But that greater intensity did arrive and was rewarded with an equaliser at the start of the second half-hour period.
Swiss international striker Ajeti, wearing the captain’s armband, collected Ewan Henderson’s pass and fired a fine right foot shot beyond Wednesday ‘keeper Joe Wildsmith.
Celtic took the lead in the 56th minute, Moffat capping his excellent display with a goal when the ball broke to him on the edge of the penalty area and he guided in a precise low finish.
Edouard, among the wholesale changes made for the final 30 minute spell, sealed the victory right at the end with a composed right foot shot across the body of Wednesday substitute Cameron Dawson.
Celtic will welcome back a tranche of their more experienced players for their next friendly against Charlton Athletic on Saturday.
Celtic: Barkas (Bain 45), Ralston (O’Connor 60), Murray, Welsh (Hjelde 60), Montgomery (McPherson 60); Soro (Connell 60), McInroy (Otoo 60); Shaw (Robertson 60), Henderson (Coffey 60), Moffat (Afolabi 60); Ajeti (Edouard 60).
Sheffield Wednesday: Wildsmith (Dawson 45), Borner (Dawodu 45), Dunkley (Galvin 45), Hutchinson (Hunt 45), Palmer (Brennan 45); Trialist (Adedoyin 45), Bannan (Dele-Bashiru 45), Luongo (Waldock 45), Green (Trialist 60); Windass (Hagan 45), Paterson (Trialist 45).