RB Leipzig's technical director Christopher Vivell believes Chelsea should sign Erling Haaland this summer.

The Borussia Dortmund striker is a key target for several top European clubs.

However, most teams are waiting until next summer, when the 21-year-old will have an active buy-out clause in his contract.

Vivell, however, believes that Chelsea should spend up to £150 million to secure Haaland this summer.

"When I look at the market and see who I would spend that much money on, he would probably be one of two," Vivell told SportBILD.

"If you can secure him now and pay that much for him, you're not making a mistake because he's still so young.

"On top of that, you have him under contract for five years, and Erling is already guaranteed something then.

"If he stays injury-free, he can dominate the next ten or twelve years like Cristiano Ronaldo."