Southampton were held to a goalless draw by SK Austria Klagenfurt, despite twice hitting the woodwork and seeing a second-half penalty saved.
Will Smallbone and Ibrahima Diallo struck the post and crossbar respectively in the first half, while Adam Armstrong was denied from the spot midway through the second period on a frustrating evening in the sparsely-populated Wörthersee Stadion.
Saints made 10 changes at the interval, as Ralph Hasenhüttl replaced his entire outfield, with only goalkeeper Alex McCarthy playing the full 90 minutes in the absence of Gavin Bazunu.
Manager Hasenhüttl fielded a young starting line-up, with Saints in action for the second time in three days, including 18-year-old Diamond Edwards and Thierry Small, 17, as the wing-backs.
Another youngster, Will Smallbone, who impressed as a second-half substitute against RB Leipzig on Saturday, went close to an early opener as Saints started firmly on the front foot.
Found in the box by Ché Adams, Smallbone took a touch and rifled the ball towards the near post from 10 yards, only to see his shot cannon against the upright.
The Irishman was instantly involved again when he spread a clever pass to the left for Nathan Tella, who played the ball into the path of the buccaneering Small to hit first time, but the teenager could not wrap his foot around the ball enough to guide his shot on target from a narrowing angle.
The hosts responded well, as Scotsman Andrew Irving switched the play to feed the run of Sinan Karweina, who dragged his shot across goal and wide.
The same pair were involved in similar fashion when Irving sent another piercing through ball in behind Small, this time held up by Karweina who waited for support from Christopher Wernitznig, who looked to beat McCarthy down by his near post but could only find the side-netting.
Saints’ bright start had rather fizzled out, though Smallbone remained a bright spark as the closest midfielder in support of Tella and Adams up front.
That was until Ibrahima Diallo won the ball in the Austrians’ half and drove forward, running beyond Tella, trading passes and pulling the trigger in the box, but his luck was out as the ball struck the underside of the crossbar and bounced back into play.
Meanwhile, Karweina was still the outlet for Klagenfurt, and darted away from Jack Stephens before drilling the ball across goal as once again either goalkeeper was spared the need to make a save.
That did change five minutes before the interval when Adams slipped the ball through for strike partner Tella, who was forced wide, giving Phillip Menzel the opportunity to make a fairly routine save with his legs.
The half-time break sparked a wave of substitutions for Saints, who were able to field a more experienced line-up for the second period.
Mohamed Elyounoussi was immediately thwarted by a last-ditch tackle by Kosmas Gkezos, before the same defender got a vital touch to turn Kyle Walker-Peters’s teasing low cross behind for a corner.
Then Stuart Armstrong fed Moussa Djenepo on the left side of the penalty area, but the winger’s shot was tame and comfortably smothered by Menzel.
Klagenfurt were once again indebted to the recovery powers of Gkezos, who found another timely challenge to dispossess Adam Armstrong after the home side were caught trying to play out from the back.
By this point the hosts had also made wholesale changes, and another was to follow on 65 minutes when Patrick Hasenhüttl entered the fray – a strapping 6ft 3in centre-forward and son of the Saints boss.
Within 60 seconds Saints were given a golden chance to break the deadlock, as Roméo Lavia’s clipped pass over the top found Walker-Peters in the box, who flicked the ball up on to the hand of Till Schumacher. Penalty awarded.
Up stepped Armstrong, a scorer against Leipzig, but his luck was out, as substitute goalkeeper Marco Knaller made a sharp stop low to his right to repel the spot-kick just six minutes after coming on.
McCarthy finally had a save of his own to make 10 minutes from time, beating away a curling shot from the corner of the area, but Saints will be frustrated they were unable to make the breakthrough at the other end.