Alexandre Lacazette is substituted so often at Arsenal due to Arsene Wenger’s faith in sports science, the Gunners boss has revealed.
He was acquired to lead the line and provide an attacking spark as a proven performer at the very highest level.
The 26-year-old has, however, seen Pierre-Emerick Aubameyang drafted in to provide fierce competition for places and his manager often chooses to haul him off in the second half of games.
Wenger is renowned for leaving changes until the final 20 minutes, with it his opinion that performance levels dip the most in that period.
The Frenchman told the Arsenal magazine on his tactical tinkering: "We know the players’ physical qualities and who we expect to drop in the second half or not. Nobody’s tired enough at half-time to be substituted for that, but in the second half you’ll see that sometimes this player will drop in the last 20 minutes.
"We have a fatigue factor coming in at different levels for everybody and we know the players who drop more in the second half than others. Some remain completely consistent and some even push upwards in the second half.
"There are players who drop up to 15 per cent in the second half, so you have to consider that in your substitutions. Even if you do make substitutions, you always try to keep one free because you know this guy could need to be substituted as well so you need to keep a place for him."
Wenger added on Lacazette, who has started and finished just six Premier League games this season: "I must say that [he] plays in a position where you sub more than say a defender.
"You substitute a striker more than you would a defender, because they always have to provoke, to defend, to attack, you have to create holes in the defences. The strikers are more subbed than others."
Lacazette opened the season with a 90-minute run-out against Leicester, but then had to wait until a 3-3 draw with Liverpool on December 22 for his next.
He has, however, managed just one goal in his last 13 appearances across all competitions and has been sidelined since mid-February with a knee problem.