Zlatan Ibrahimovic. Photo: Darren Staples/Reuters

LONDON - Zlatan Ibrahimovic’s contract at Manchester United includes a gigantic bonus for the number of goals he scored.

Sportsmail can disclose the breathtaking incentive which was worth up to £143,000 a goal, depending on when they were scored. This is on top of his £367 640-a-week basic pay.

In total, Ibrahimovic earned £2.86 million in goal bonuses before suffering anterior knee ligament damage against Anderlecht last month. His £19m salary and bonuses have made him the highest earner in Premier League history.

His contract includes incremental bonus rises for the number of goals he scored - designed to act as motivation for him to reach the 20-goal mark for the campaign.

The 35-year-old ended up with 28 and Sportsmail can break down exactly how Ibrahimovic secured the bonus increases.

United split his goal targets into four categories, with substantial increases each time he triggered them. The first, for up to five goals, was worth £47,000 each time he hit the net. His first payment came in the Community Shield against Leicester on August 7.

He reached the five-goal target on September 10 against rivals Manchester City and then pocketed £79,000 with each goal until reaching 10. By the end of November, he was on £111,000 a goal.

Photo: Reuters / Andrew Yates

Goals 16 to 20 were rewarded with a bonus of £143,000 each and scored between the victories away at West Brom on December 17 and Leicester City in the first week of February.

From there, his bonuses were reduced to £119,000, indicating that 20 goals was United’s target.

Ibrahimovic’s knee injury may cost him a guaranteed second season under Jose Mourinho at Old Trafford — an extension would have been activated if he had started 31 Premier League games.

Photo: Francois Lenoir/Reuters

He managed 27, having being named as a substitute only once in a league match for which he was available. Ibrahimovic took all of United’s penalties when on the field and often took charge of free-kicks within shooting distance.

He is currently in America with agent Mino Raiola and personal physio Dario Fort having had successful surgery on his knee, which could keep him out of action until 2018. He could remain in Pittsburgh as part of the recuperation process, with United open to the idea of him completing his rehabilitation at Carrington.

Breakdown of the bonus payment plan:

* £236,000 (£47,000 a goal) for his first five United goals

* £395,000 (£79,000 a goal) for goals 6-10

* £555,000 (£111,000 a goal) for goals 11-15

* £715,000 (£143,000 a goal) for goals 16-20

* £925,000 (£119,000 a goal) for goals 21-35. Ibrahimovic ended up with 28 United goals

Total goal bonus = £2.86m