The signing of Kai Havertz is one that's attracted envious gazes from Chelsea's rivals.
It's a deal that's cost the Blues a pretty penny - £72m in total - but it's also one that could help the club challenge for the Premier League title in the near future.
At the age of just 21, Havertz is already one of the world's finest attacking midfielders.
In his 150 games with Bayer Leverkusen's first-team, the German international scored 46 goals and contributed with 31 assists.
Those numbers are mighty impressive for an forward-thinking midfielder, Frank Lampard-esque you might say.
However, the one downside of Havertz's arrival is that Mason Mount - a Chelsea youth product - may struggle for game time.
Journalist Christian Falk tweeted today that Mount was unhappy that he has an 'expensive rival' in his position.
But it seems the reports from Germany are not true, because Mount's father Tony has responded emphatically to the accusations.
Tony tweeted the world 'bull' followed by an accompanying emoji in reply to Falk.
Well, that settles that then.
While Mount will likely not be in Lampard's preferred starting XI in 2020/21 after the arrivals of Havertz, Timo Werner and Hakim Ziyech, he still has a significant role to play in this Chelsea squad.
Mount was a regular presence in the Blues' starting XI last season, scoring seven goals and notching five assists in his 37 Premier League appearances.
The 21-year-old's favoured position is as a central attacking midfielder, but he's more than capable of playing out wide.
With a long season to come and Mount's known versatility, you feel certain the Englishman still has a pivotal role to play at Stamford Bridge for the foreseeable.
After all, Lampard is a huge fan of the player he has nurtured with Derby and the Blues over the past two years.
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