Bruno Guimaraes has now rescued Arsenal twice in three Premier League matches, coming off the bench to score the winner in a 2-1 comeback victory over Leeds at Emirates Stadium on Saturday — but celebrations were tempered by concerns over Ecuador international Piero Hincapie, who was carried off during the post-match warm-down.

Guimaraes delivers from the bench again

The £75m summer signing had already made his mark with the opening goal in Arsenal's 2-0 win at Sunderland in September. Against Leeds, with Arsenal trailing after the 55th minute, Riccardo Calafiori levelled matters before Guimaraes — making his first full home appearance — struck the decisive blow.

It was a fifth win in six league games for Mikel Arteta's side, drawing them level on points with leaders Manchester City. Yet the manner of many of those victories has raised questions, with Arsenal falling behind in three of their last four league matches and requiring a David Raya penalty save just to avoid trailing at Sunderland.

Arteta was blunt in his assessment of Guimaraes, whose full league debut had come in Arsenal's 3-0 defeat at Brighton: "He wasn't at that level against Brighton, and this is the level for Arsenal. Every week, every game, every minute, every action, you have to be at that level. Today was much better."

Guimaraes became the first player to score twice from the bench in the Premier League this season, with both goals arriving from outside the box.

Attacking questions linger

Arteta's team selection raised eyebrows. He started Kai Havertz up front despite the German returning early from international duty with a hamstring problem, leaving Viktor Gyokeres — who had scored four goals for Sweden during the break — on the bench again. Gyokeres is still waiting for his first Premier League start of the season, and his brief cameos have not yet made a convincing case for him.

On the wing, Arteta turned to Noni Madueke after winger Christos Tzolis picked up a hamstring injury on international duty with Greece, and Eberechi Eze found himself out of form. Madueke had missed out on the latest England squad through lack of minutes, but Arteta revealed he had been "the best player in training for the last 10 days" — and Saturday represented an opportunity to translate that form to the pitch.

Defensive concerns and the Hincapie worry

Arsenal's defence, the bedrock of their title win last season, remains a work in progress. The Gunners conceded just five times across the entire league campaign last term but have already shipped five in six this season. The absence of William Saliba through injury continues to test the backline, with summer signing Ezri Konsa — who arrived from Aston Villa for £55m — still adjusting to his new environment.

Calafiori offered a bright spot, scoring Arsenal's equaliser — his first league goal of the season — while no defender in the Premier League has contributed to more goals this campaign than the Italian, with one goal and two assists to his name.

Now the question of Hincapie's fitness adds to that concern. The Ecuador defender came on late as a substitute but was helped off the pitch during the warm-down after the final whistle.

Arteta did not shy away from the difficulties his team have faced: "The last time we put our shirts on, something was missing. And we need to be very conscious of that. From being exceptional and being the champions to being extremely average — like in that game — is a really thin line."

Ally McCoist, summarising for TNT Sports, acknowledged both sides: "It was a great game of football. Leeds were brilliant for one hour. Mikel Arteta made changes when he needed to and the substitutions gave Arsenal what they needed. That's what champions do."