Why De Bruyne?
Wolfsburg signing De Bruyne would be a statement of intent to Diego: Extend your contract or risk being frozen out.
"The clubs who want me now will still want me in the summer," Diego said, as per Kicker (h/t Sky Sports). "One thing's for sure at the moment, I'm staying at least until the end of the season."
Wolfsburg should not give Diego playing time if he is going to walk out on the club.
De Bruyne is a creative, two-footed, make-something-happen footballer who would fill the playmaking void left by Diego should the Brazilian play out his contract which expires at the end of the season.
Diego's magic can be emulated by De Bruyne—his own magic was on show last season as a Werder loanee when he dinked the ball over Stuttgart centre-back Georg Niedermeier, raced into the box and lobbed goalkeeper Sven Ulreich.
Maximilian Arnold is a natural goalscorer, three goals in six league games last season and five goals in 11 games this season, so he needs to start as a deep-lying forward behind No. 9 Ivica Olic.
De Bruyne's incisive passing and Arnold's knack for scoring may produce a productive combination in the long-term for Wolfsburg.
There were only five players in the Bundesliga last season who averaged more scoring chances created per game than De Bruyne (2.6): Ribery (3.2), Jefferson Farfan (3.1), Toni Kroos (2.8), Max Kruse and Hiroshi Kiyotake (2.7).
De Bruyne has a penchant for crosses, attempting 244 in 33 league games, but when you see his perfect cross to Marouane Fellaini during Belgium's 4-2 win over the United States, you understand why De Bruyne is cross-happy.
Trying to Figure Out Wolfsburg's Mindset
If Chelsea sell De Bruyne, who has played 132 minutes of Premier League action this season, for £18 million to Wolfsburg when he has no future under Blues manager Jose Mourinho, then you must give props to Chelsea management.
It is shrewd business as Chelsea will be making an £11 million profit on De Bruyne.
Yet you have to wonder what Wolfsburg are thinking.
They won the 2008-09 Bundesliga based mainly on three unbelievable transfer steals: Grafite (Le Mans; £4.6 million) Edin Dzeko (Teplice; £3.3 million) and Zvjezdan Misimovic (Nurnberg; £3.2 million).
£11.1 million in return for 61 goals and 41 assists that season.
In modern historical Bundesliga context, the trio of Grafite, Dzeko and Misimovic are placed in the same sentence as Stuttgart's magic triangle (Fredi Bobic, Giovane Elber and Krassimir Balakov).
Here are three questions Wolfsburg should ask themselves before they complete the £18 million transfer for De Bruyne (he would be £1 million more expensive than the £17 million Bayern Munich paid Marseille for Franck Ribery in 2007).
Will De Bruyne reach Ribery's level within two seasons?
Are Wolfsburg Bundesliga contenders after signing De Bruyne?
Can Wolfsburg justify De Bruyne's transfer fee based on his recent performances?
If the answer to all three questions is no, then Wolfsburg need to walk away from the negotiating table.
In his three seasons, Wolfsburg placed 10th, ninth and 15th.
Resentment from Wolfsburg management was inevitable when D'Alessandro, the high-profile, big-money player, underperformed.
"I don't need 11 Maradonas on the field," then Wolfsburg manager Klaus Augenthaler said, as per Jon Brodkin at the Guardian. "I need players who are willing to fight for the team."
It was fraught with danger for Wolfsburg to expect D'Alessandro to be world class week in, week out.
Unless Wolfsburg are going to alleviate De Bruyne's workload by signing a world-class No. 9—say Porto's Jackson Martinez or Manchester United's Chicharito—then it's risky to buy De Bruyne for £18 million.
What De Bruyne's Transfer Means to Chelsea
Assuming De Bruyne's proposed £18 million transfer from Chelsea to Wolfsburg doesn't collapse, this is a step in the right direction for Blues management in dealing with world-class prospects who are not an integral part of the first team.
Rather than continually loaning them out until their contract expires or abandoning them in the reserves, be proactive and coax opposing clubs into submitting inflated transfer fees.