5 most profitable transfers in Chelsea's history

Eden Hazard was one of the best players in the Premier League while playing for the Blues.

Chelsea, owned by Russian billionaire Roman Abramovich, are one of the smartest football clubs in the world. Their business model not only helps them earn success on the field, but also off it.

It was only after their takeover by Abramovich that the club started earning accolades regularly. Credit goes to the Russian for his vision and how he has gone about transforming the Blues' fortunes.

Chelsea are shrewd with their transfers

Chelsea have been quite intelligent with the players they have invested in. Moreover, they always send out a lot of players on loan to aid in their development.

However, when the time comes, the Blues don't hesitate in selling their key players, and that has turned out well for them in most cases. In the process, they have amassed heavy profits on those sales. On that note, here's a look at the Blues' five most profitable transfers over the years."

Note: All values are as per Transfermarkt.

#5 Diego Costa - £19.8 million

Diego Costa was a beast of a striker when he played in the Premier League.

There are very few players with the prowess of Diego Costa. The tall striker signed by Chelsea for £34.2 million in 2014 after an impressive spell with Atletico Madrid.

Using his strong physique and excellent finishing abilities, Costa fared well for the Blues. In his three seasons at Stamford Bridge, he scored 52 goals in 89 Premier League games. He helped the club win two league titles, and was also named in the PFA Team of the Year in the 2014-15 season.

Vintage @diegocosta #OnThisDay in 2016! 💪 https://t.co/GlzARv3jml

After falling out with then Blues manager Antonio Conte, Costa left the club, and rejoined Atletico Madrid in the summer of 2017. The transfer fee involved was £54 million, helping the Blues make a profit of £19.8 million on his sale.

#4 David Luiz - £22.05 million

David Luiz had two spells with the London club.

David Luiz has had an interesting career. His fine performances with Benfica helped him earn a move to Chelsea in 2011 for £22.5 million.

Thanks to his aggressive approach, intense tackling and amazing aerial abilities, Luiz was quite effective at the back. He was also reckless at times, and made some poor decisions, but he was largely useful to the club's cause.

He won the UEFA Champions League and Europa League with the London club before deciding to move to Paris Saint-Germain.

Also wanted to wish my friend & Ex @ChelseaFC player @DavidLuiz_4 a very happy birthday today. Here are his stats for Chelsea. 💙 #CFC

2️⃣4️⃣8️⃣ Games
1️⃣8️⃣ Goals
1️⃣2️⃣ Assists
🏆🏆 Europa League
🏆🏆 FA Cup
🏆 Champions League
🏆 Premier League https://t.co/5Ln2ppHdLy

The French club signed Luiz in 2014 for £44.55 million, helping the Blues make a profit of £22.05 million on his sale. The Brazilian centre-back returned to the Premier League club for a second spell in 2016.