Scottish champions Celtic slipped to a shock 2-0 defeat at St Mirren on Sunday afternoon, with the Parkhead outfit seeing their 38-game unbeaten run in the league come crashing to an end following what was a dismal display in Paisley.

364 days on from their last defeat in the top-flight - with that having come away at Livingston - Ange Postecoglou's men produced a rare below-par performance against a courageous Buddies outfit, with the title-winning coach left to rue his decision to heavily rotate his side.

One of the only real injury-related alterations for the clash with Stephen Robinson's side saw Stephen Welsh come in to replace the stricken Cameron Carter-Vickers, with that change ultimately proving costly as the American's absence left a notable void.

The former Tottenham Hotspur man - who signed for the Old Firm side on a permanent deal over the summer - has been in imperious form over the past 12 months or so in Glasgow, having formed an "immense" partnership with teammate Carl Starfelt at the heart of the backline.

With the Sweden international also unavailable due to a knee issue, it saw a relatively untested pairing of Moritz Jenz and the aforementioned Welsh start in defence, with that youthful duo subsequently failing to deal with the imposing, physical presence of both Jonah Ayunga and Curtis Main.

The latter man, in particular, proved a real handful as he simply "bullied" the Hoops defence, in the words of journalist Josh Bunting, with the visitors' backline having looked a real "mess" on the day.

The defensive axis of Jenz and Welsh had looked "all over the place" - as per Bunting - although it was the Scotland U21 international who particularly disappointed, having been "weak" in attempting to defend Ayunga's second-half effort, according to Sky Sports commentator Andy Walker.

The 22-year-old appeared to fling himself to the ground after minimal contact from Main inside the area in the build-up to the hosts' second goal, with it hard to imagine Carter-Vickers having been so easily outmuscled.

The academy graduate also showed his failure in possession as he lost the ball on ten occasions, with the £1.35m-rated man having done little to stake his claim for a more regular starting berth on what was just his second league outing of the season so far.

With Postecoglou now having the international break to ponder his team selection for the upcoming clash against Motherwell on 1 October, it would well be a surprise if the 57-year-old were to name Welsh in his starting lineup, with the £10.5k-per-week youngster having distinctly underwhelmed yesterday.