The impact sub changes the course of a game.

There were times last season when Mikel Arteta, in Arsenal’s second consecutive title race, would look to a depleted bench in hard times and options would be found lacking.

They relied on set-pieces, but after a summer of reinforcement in attacking areas – including Noni Madueke and Eberechi Eze – it is a player whose future has been a hot topic who is proving to be one of the Gunners’ most clinical attackers.

Gabriel Martinelli was voted Arsenal’s player of the month for September because of two standout moments.

It took the 24-year-old just 37 seconds to come off the bench and score the opener against Athletic Club in the Champions League, and he then provided the assist for the goal by Leandro Trossard – another of Arsenal’s ‘finishers’ – that sealed the 2-0 victory. And fellow sub Trossard had laid on the first goal for his team-mate.

Only four Premier League players have contributed three or more goals and assists from the bench this season in all competitions, and Martinelli and Trossard are two of them.

When speaking about the mentality of the players left on the bench, Arteta has said: “They are at least equally important, or more important. We have discussed that.

“The finishers are going to be more important this season sometimes than the starters.”

Finishers or game-changers are a concept taken from rugby union to describe players who start the match on the bench.

Though Trossard tops the list of goal contributions above, Martinelli’s so far have arguably been more memorable and in big-game moments.

As well as his assist and late goal in Bilbao, the Belgian laid on the third goal in a routine 3-0 win over Nottingham Forest and scored the second late on in the 2-0 victory at Port Vale in the Carabao Cup.

Martinelli’s other crucial moment as a sub, however, came against Manchester City in the Premier League, rescuing what could prove to be a huge point in injury time.

The superb, lofted finish after a ball over the top ended a move that took advantage of the space behind City’s defensive line with Martinelli’s direct running.

This perhaps highlights a key reason for the success of Martinelli being deployed largely in the latter stages of matches: he can be at his best when the game is opened up. Transitions are more frequent and there is often more opportunity to catch opponent on the break, which is how his goals off the bench this season have come about.

Martinelli has only started two of the Gunners’ seven Premier League games so far this season – both in August against Manchester United and Liverpool – but has been introduced as a substitute in four of the other five.

He also featured from the outset against Port Vale in the Carabao Cup third round and started – and scored the opener – in the home Champions League win over Olympiacos.

Additional data collection and visualisation by Jordan Butler