THE San Siro once played host to one of Arsenal’s greatest ever European victories.In November 2003, Arsene Wenger’s majestic Invincibles smashed Javier Zanetti’s Inter Milan 5-1 thanks to a Thierry Henry-inspired away-day Champions League masterpiece.Hakan Calhanoglu converts from the penalty spotCredit: GettyIt was enough to separate the sidesCredit: GettyYet 21 years on, this was anything but as Mikel Arteta’s Gunners fell to a miserable third defeat in six games in all competitions – one more painful bump in the road this term.In the new 36-team league format, with four games still to play, this first Euro defeat – thanks to Hakan Calhanoglu’s first half injury time penalty – is not fatal in their quest to qualify.Instead, it simply acts as another confidence-shattering and pressure-heaping result for a group of players that look weighed down by expectation.Arteta’s Arsenal are not in a good place. Their belief drained, their optimism fading, all before what now looks to be a serious season-definer away at Chelsea on Sunday.READ MORE IN footballLose that, and they could be TEN points off leaders Liverpool. Title race over in mid-November?Among those San Siro legends in red and white were Henry, recently departed Sporting Director Edu and Robert Pires. Generational heroes.There were none on show last night against Simone Inzaghi’s brick-wall Inter set-up. An Arsenal team that once sparkled is beginning to lose its shine.Arsenal are now at the backend of their injury ‘crisis’ with skipper Martin Odegaard on the bench – his first squad involvement since August 31 after a prolonged ankle issue.Most read in FootballHowever, Declan Rice was watching this one from home with a foot problem, allowing Thomas Partey to slot back into midfield and Ben White to return to right back.The visitors tried to start on the front foot only to be hit by an early scatter gun of Inter chances. Denzel Dumfries controlled a cross in the box before unleashing a cannon of a volley off the bar.Hilarious moment Mikel Arteta ‘fines’ journalist during press conference as brutal discipline rules apply to everyoneCalhanoglu then skimmed a bobbled shot from range just wide of David Raya’s right-hand post. The Spanish keeper was coming under attack from all areas.The hosts could smell blood, as could the brilliantly mad supporters filling this cathedral of noise. Partey was soft again but Mehdi Taremi’s cross was just cut out.Arsenal were being made to fight for every opening, but even when they were presented with a chance, it was scrappy and unconvincing.Frustration brewed. Before a rare foray forward and a first corner, Gabriel was booked – as well as his marker Lautaro Martinez – for a pretty petty shoving match.There were soon signs of life, Saka showing incredible strength on the halfway line against Yann Bisseck to send Gabriel Martinelli on a gallop down the left.The Brazilian’s cross was a yard too heavy for the incoming Mikel Merino. Saka then had some space to attack down the right, firing a shot of his own straight at Yann Sommer.Another Martinelli cross was more accurate as Merino showed bravery in the air. As a reward, he was clobbered by a heavy-fisted Sommer.Merino did well to get back up quickly while Sommer awaited a VAR check. The Swiss shot-stopper appeared to get a slight glance on the ball before taking Merino’s head off.Inter looked to be content with sitting in as Arsenal’s influence grew.Merino was adjudged to have handled itCalhanoglu’s spot kick separated the sidesCredit: AFPThree successive corners towards the end of the half came to nothing and Inter countered forcing William Saliba to put in a surprisingly unpunished timely foul.Taremi’s flick on hit Merino’s arm and in response, referee Istvan Kovacs pointed his arm to the spot as the clock ticked over to first half injury time.Merino looked baffled, and rightly so. His arm was barely outstretched and had little to no time to react or get out of the way from such close range.This was a harsh call, but one we have come to expect in the Champions League with European officials in charge, even if VAR did take their time in deeming it fair.It was an agonising wait for Calhanoglu with the ball on the spot, not that it showed in his finish down the middle.Raya was the hero in Bergamo with his spot-kick double-save to earn a 0-0 draw at Atalanta in Arsenal’s opener, but he could not produce a similar rescue act here.Arsenal trudged into half-time. To get anything, they would have to score against a side with more Champions League clean sheets than any other side over the past three seasons.Arteta sought a reaction, bringing off Merino for Gabriel Jesus and shoving Kai Havertz back into midfield, and got just that apart from the final finish.Saliba and Gabriel came close from corners, the latter seeing a flicked effort cleared off the line, and a dinked curler from Havertz almost caught out Sommer.READ MORE SUN STORIESHavertz then found space in the box with a snatched volley superbly deflected wide by Bisseck. Inter stood firm and were typically Italian in their slowing down of the game.It made Arteta irate, booked for his protests. The pressure is mounting to turn this around, and he knows it.Mikel Arteta looks on in frustrationCredit: Getty More