AC Milan have been on a sharp decline ever since their last Serie A triumph in 2010/11.

The club have failed to win a major trophy in the past nine years and now regularly miss out on qualifying for the Champions League.

In case you had forgotten, this a footballing powerhouse that has won Europe's most prestigious prize on no fewer than five occasions.

It's a sad sight to see such a famous institution fading into obscurity and there are a number of viable reasons as to why they have fallen from grace.

But one of the key ones has been their lack of a top-quality striker.

Ever since Pippo Inzaghi vacated the club's number nine shirt in 2012, the jersey has been a poisoned chalice.

After Krzysztof Piatek's departure to Hertha Berlin was confirmed today, it continues a trend of no AC Milan striker holding the number nine shirt for more than a single season.

AC MILAN'S CURSED NUMBER NINE SHIRT

2012: Alexandre Pato - left after just half a season

After being handed the number nine shirt following Inzaghi's departure, Pato's career with Milan completely fell away.

He mustered just two goals in seven games while donning the famous jersey and left in January 2013 for Corinthians.

2013: Alessandro Matri - left after just half a season

Matri took the reins in the summer of 2013 after signing from Juventus and it would be catastrophic failure for both player and club.

In 18 appearances, he scored just one goal and was hastily shipped off to Fiorentina in January 2014.

2014: Fernando Torres - left after just half a season

Torres joined Milan on a two-year loan in the summer of 2014, but he continued his dismal Chelsea form over in Italy.

His 10 appearances sporting the number nine yielded one single goal and he was off back to Atletico Madrid in the January 2015.

2015: Mattia Destro - left after just half a season

Destro was brought in on loan to fill Torres' boots, which wasn't exactly hard given the Spaniard's horrendous form.

The Italian didn't to much better though, scoring three times in 15 appearances. Unsurprisingly, his loan was not made permanent.

2015: Luiz Adriano - lost the number after one season

Surely a bit of Brazilian flair will stop the rut? Absolutely not. Adriano scored just four times in his 26 appearances wearing number nine and almost left the club after six months for China - before the deal with Jiangsu Suning fell through at the last minute

He was handed the number seven shirt in 2016/17 and then failed to score in seven Serie A games, tragic. Adriano finally left for Spartak Moscow in January 2017.

2016: Gianluca Lapadula - left after just one season

Back to an Italian to guide the club back to its previous status, a recipe for success? Of course not.

Lapadula at least managed eight goals in his 29 appearances, but he didn't last long. He was loaned to Genoa in the first month of 2017, before signing for them permanently in 2018.

2017: Andre Silva - left after just one season

The only player to reach double figures in the number nine shirt since Inzaghi's departure, bravo Andre! The Portuguese is still technically a Milan player as well..

He was loaned to Sevilla in the summer 2018 and is now at Eintracht Frankfurt on a temporary basis for this season.

2018: Gonzalo Higuain - left after just half a season

If any player was going to buck the number nine trend, it was going to be Higuain. A serial goal scorer with Napoli and Juventus, the Argentine ticked every single box possible.

But 22 games only produced eight goals and when Maurizio Sarri and Chelsea came calling in January 2019, the seasoned striker was off on his travels once more.

2019: Krzysztof Piatek - left after just half a season

When the Pole first arrived, he took the number 19 shirt and was an instant success and was the fastest to register six goals in Milan's history.

But after taking the number nine shirt in the summer, it's been a one-way ticket down. His last 20 appearances have produced just five goals and he's now been sold to Hertha.

So Zlatan Ibrahimovic and Rafael Leao, you have been warned - stay away from the number nine shirt!