England legend Stuart Pearce has shared why Kai Havertz has now become a nightmare for defenders since joining Arsenal. The Germany international was the biggest surprise signing in north London last summer as Arsenal paid a surprising £65m to bring Havertz from Chelsea to the Emirates Stadium, where the versatile attacking midfielder had struggled. Early performances were not that convincing for Havertz at Arsenal, yet a change to playing at centre-forward at the start of 2024 changed everything for the 25-year-old, who went on a tear between then and the end of the season. And Pearce has now…