Arsenal knocked Porto out of the Champions League in a fiercely contested two-legged tie, but they were far from their usual selves.
Mikel Arteta’s side have been scoring freely in the Premier League, but managed just one goal across two games and extra time against Porto, and needed penalties to reach the quarter-finals.
Arsenal found themselves unable to carve Porto’s stubborn defence open, and were also frustrated by their ability to run down the clock and waste time.
Despite some of Arsenal’s attackers struggling, Arteta did not make a single substitution until the 83rd minute, when Gabriel Jesus, who should perhaps have started, came on to replace Jorginho.
Although Leandro Trossard scored, he mostly struggled on the wing, with Porto’s physicality blocking him from attacking the box beyond his goal.
Even though he struggled, Trossard lasted until the 105th minute, in a surprise decision which had shades of two European knockout defeats under Arteta.
Late Arsenal substitution of Trossard reminiscent of Fabio Vieira and Alexandre Lacazette
Arteta’s home European knockout record is poor, with Porto his first win in such circumstances at the Emirates.
Trossard lasting 105 minutes until Eddie Nketiah came on to replace him, with Reiss Nelson and Emile Smith Rowe on the bench, caused some surprise, but Arteta has made similar mistakes before, which ultimately proved more costly.
When Arsenal were eliminated by Olympiakos at the end of extra time in 2020, striker Alexandre Lacazette lasted 105 minutes at the Emirates, despite putting in an exceptionally poor performance, and many argued that he should have been substituted earlier.
Fabio Vieira also struggled in last season’s defeat to Sporting Club De Portugal, but somehow lasted 103 minutes before Martin Odegaard was introduced to the game.
Although Arsenal won the resulting penalty shootout this time, Arteta’s substitutions in extra time did little to help win the game before the possibility of a shootout.
Mikel Arteta needs to trust his bench more

With Bukayo Saka also struggling in the game, many argued that Jesus could have come on earlier, or one of Nelson or Vieira could have made an impact on the match.
Rotation will be key when the fixtures pile up towards the end of the season, and this could have been a good opportunity for Nelson to inject some pace into the side which was otherwise lacking.
The lack of decisive substitutions cost Arsenal in Europe in the past, and the opposition sides all made changes throughout the latter stages of the games to keep their team fresh, and it showed against Porto as Arsenal struggled physically by the end of the game.
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