Chelsea are reportedly keen to sign Bayer Leverkusen attacker Kai Havertz this summer due to concerns over Callum Hudson-Odoi's development at Stamford Bridge.
Hudson-Odoi penned a new long-term deal with the Blues last September, but the Englishman has struggled to impress this season, scoring just once in 18 Premier League appearances.
According to 90min, the Blues have 'stepped up their pursuit' of Havertz as they are worried by their academy's product perceived lack of progress during the 2019-20 campaign.
Havertz enjoyed an excellent 2019-20 campaign for his German club, scoring 17 times and providing nine assists in 43 appearances in all competitions.
The 21-year-old has less than two years left to run on his contract at BayArena, and it is thought that he will seek pastures new during this summer's transfer window.
Chelsea have already secured deals for Hakim Ziyech and Timo Werner ahead of next season as Frank Lampard looks to build a team capable of challenging for the Premier League title.
