Dortmund (Germany) (AFP) – Pierre-Emerick Aubameyang says he had a point to prove after scoring his first Champions League hat-trick, but it leaves Borussia Dortmund wondering how long they can keep him.

The Gabon striker’s three goals against Benfica in Dortmund on Wednesday sealed a 4-1 aggregate last 16 win and capped a man-of-the-match display.

The performance redeemed his first-leg howler when he missed four clear chances in a 1-0 defeat.

Three weeks ago in Lisbon, Dortmund coach Thomas Tuchel hauled Aubameyang off after his star missed a second-half penalty in a miserable first-leg display.

But the hot-shot was all smiles after his second-leg hat-trick swung the last 16 tie Dortmund’s way. 

“I was very sad after the first leg, made many mistakes over the whole match and wasn’t at all happy with my game,” Aubameyang said after Dortmund’s impressive victory.

“So I wanted to show my team-mates that I can play much better, so I am delighted that we won and are through.”

Aubameyang has now scored seven times in his last three games and has seven Champions League goals in as many matches this season.

He is now on 28 goals for the season with Dortmund in the Champions League’s last eight for the first time since 2014.

“It was a sensational performance,” enthused Tuchel, delighted to see his star asset back in form after a dip following Gabon’s early Cup of Nations exit at the start of the year.

Aubameyang’s goals are crucial for Dortmund’s aspirations this season as they look to repeat their 2013 Champions League final appearance.

– Real Madrid promise –

“The goals he scores for us every week are important for the team’s success and we’re very happy to have him,” said Erik Durm, who set up Aubameyang’s third goal against Benfica.

But how much longer can Dortmund keep him?

It’s been well documented that the 27-year-old made a promise to his grandfather, just before he died, that he would one day play for Real Madrid.

And in two separate interviews in January, Aubameyang admitted he is considering leaving at the end of the season to ‘reach the next level’ in his career.

He also said the Spanish league appeals to him more than England’s Premier League, although he insisted he would never join German rivals Bayern Munich.

His honesty prompted Dortmund’s bosses to tell him to cut out any exit talk.

Aubameyang has a contract until 2020 with Dortmund, who can command a much higher fee for him than the 13 million euros ($13.7m) they reportedly paid Saint-Etienne in 2013.

Estimates put his current market value at 65m euros.

Having had to watch Robert Lewandowski leave for arch-rivals Bayern in 2014 on a free transfer, Dortmund will not want to make the same mistake twice. 

Their scouting department are clearly doing something right.

– Talent factory –

Aubameyang, the Bundesliga’s top-scorer with 21 goals, is currently battling Lewandowski to be Germany’s hot-shot this season.

Borussia bought Lewandowski from Lech Poznan in 2010, then recruited Aubameyang in 2013, but now US teenager Christian Pulisic is showing signs he could become their next superstar.

The midfielder, only turns 19 in September, was plucked from Pennsylvania in 2015 and nurtured in Dortmund’s academy.

The senior US international was outstanding against Benfica, a constant threat having only started because of injury to Germany winger Marco Reus.

Pulisic set up Aubameyang’s fourth-minute opener, then scored the Germans’ crucial second with a deft chip on 59 minutes.

At 18 years, five months and 18 days, he is the youngest Dortmund player to score in the Champions League.

His goal put Dortmund ahead for the first time on aggregate against Benfica and with the shackles off, Borussia ran riot.

Aubayemang added two more goals having preciously missed three clear chances. 

“He is incredibly cool under pressure, he justified our faith in him at the right time,” said Tuchel of Pulisic, the latest gem Dortmund has unearthed.