Striker Nicolas Jackson was at the heart of one of the summer window's most dramatic transfer stories, but ultimately got his wish by joining Bayern Munich on loan from Chelsea.

It was not lost on anyone involved in the deal that the 24-year-old would quickly face his parent club when Bayern host Chelsea in their opening Champions League game on Wednesday.

Those who helped complete the on-off-on deal had plenty of time around a frantic deadline day to discuss his debut for the German super club in Europe's premier competition.

Jackson remained in Germany throughout as a deal was agreed on Saturday morning, before permission to have a medical was cancelled because of a serious hamstring injury to Blues striker Liam Delap.

But the move was back on by Monday's deadline.

During that time, Jackson told his advisors he was looking forward to facing, and hopefully scoring against, Chelsea.

That feeling sums up some of the emotions as Jackson left Stamford Bridge.

He is likely to feel he has a point to prove to some of the Chelsea fans that never fully embraced him, notably booing him off during former manager Mauricio Pochettino's tenure.

Some of the management, including head coach Enzo Maresca, also began to lose trust in him after two red cards against Newcastle United in the Premier League and Flamengo in the Club World Cup at the end of last season.

That fracturing of the bond between Jackson and Chelsea, along with the arrival of strikers Joao Pedro and Delap, pushed him out of west London.

At his unveiling at Bayern, Jackson said: "It was tough - a tough time. Difficult moments in those last days. But I was very confident I will stay here because this is where I want to play and want to be.

"Max [Eberl, Bayern sporting director] and the coach really wanted me. It was very tough but in the end we got it, so I'm very glad.

"I've watched Bayern all my life. It was a dream to join this massive club. When they called me I was excited and ready to come and play for them."

Yet, this on-off-on transfer saga is only over for now, because the deal - a loan with an obligation to buy - does not appear watertight.

Jackson joined Bayern Munich on deadline day for a £14.3m loan fee - close to a world record amount for a temporary deal - with a conditional obligation to buy for £56.2m.

Only the loan moves that took Alvaro Morata from Chelsea to Atletico Madrid and then from the Spanish club to Juventus commanded bigger fees.

However, according to widespread German media reports, the conditions to make the loan deal permanent are difficult to meet.

Uli Hoeness, the former striker who is an influential figure on Bayern's board, told Sky Germany during the international break: "He won't play 40 games from the start.

"We still have 32 Bundesliga games. If we reach the Champions League final, which we hope we will, that adds 13 games. The total is 45 games.

"The DFB Pokal [German Cup] games do not count. So he would have to start all these games. He will go to the Africa Cup of Nations in January, so he can't start 40 games."

Further clarification has been given that any appearance of 45 minutes or more would count as a "start" for Jackson.

Hoeness also claimed Jackson's Epic Sport agency, led by Ali Barat, paid the extra £1.3m added to the loan fee by Chelsea in the 48 hours before deadline, while leaving open the possibility that the Senegal striker could return to west London next summer.

When asked about the arrangement at his unveiling press conference, Jackson said: "It's not my decision, my job is just to play on the pitch, make my team win and score as many goals. My focus is only on trying to win big things."

Regardless, Chelsea are pleased with the finances involved and such a high loan fee could incentivise Bayern to buy Jackson next summer.

Bayern sources have also indicated that, if Jackson performs well and displays a positive attitude over the year-long loan, he will find a permanent home in Bavaria.

Their plan is for him to both compete with and complement star striker Harry Kane.

Jackson made his debut as a half-time substitute for the German champions during their 5-0 win over Hamburg on Saturday, replacing Serge Gnabry and playing alongside the England captain.

"I thought he looked sharp," said Kane. "In training, he's looked really good. It's not easy coming into a team like us when we're so well-drilled.

"He physically is very strong and fast. And if he plays, he'll be eager to impress. But I don't want to put too much pressure on him too soon.

"He knows he's working his way into the team. So far he's had a great attitude and the willingness to learn is the most important thing."

Jackson can play as a number nine or on the left wing, so has options in terms of position. And at Bayern, he escapes the pressure of needing to be the main goalscorer, while his proximity to the England captain can only benefit him in the future.

"My wish is that he scores a lot of goals for us. I think he'll achieve that," said Bayern boss Vincent Kompany.

The ball is now in Jackson's court. He can either impress and stay at one of the world's biggest clubs or follow a similar path to Jadon Sancho, who returned to Manchester United for a £5m penalty fee as Chelsea escaped their previous £20m obligation-to-buy agreement.

Both Chelsea and Jackson's entourage argue the forward's time at Chelsea was a success.

Chelsea banked on three months of exceptional form at Villarreal and decided to trigger his £32m release clause in 2023. He had more than doubled in value over in a two-year period.

Jackson had only been a professional footballer for five years - six years prior to his move to Chelsea, he was playing on sandy amateur pitches in his Senegalese hometown of Ziguinchor.

Everyone knew Jackson was a rough diamond, having played just 1,758 minutes of top-flight football, but he quickly established himself as Chelsea's starting striker.

Understandably, given the pace of his rise, there were times when Jackson struggled.

According to Opta data, Jackson underperformed his expected goals by a score of -7 over the past two seasons, which is the second-worst total in the Premier League, behind only Leeds United striker Dominic Calvert-Lewin.

Poor finishing drew criticism from fans, and he is known to have suffered under that pressure. Jackson would have runs of scoring goals but then experience long barren spells.

When asked about his exit, Maresca said: "Nico is a Bayern Munich player. I sent him a message and wished him all the best. He worked well when he was here. That's all I can say."

But Jackson also outscored Chelsea legend Didier Drogba in his first season - netting 14 goals to the Ivory Coast striker's 10. He then scored 21 goals in his first 50 games to equal one of Africa's great strikers at Stamford Bridge.

The Blues are likely to make substantial profit, whether his move is made permanent to Bayern or he eventually ends up elsewhere, so Jackson and Chelsea's scouting team have some justification in believing his time at Stamford Bridge was a success.