Chesea and Manchester United are monitoring Wolfsburg left-back Ricardo Rodriguez in their quest to replace ageing stars Ashley Cole and Patrice Evra.
Rodriguez is proving a sensation in Bundesliga this season and has been one of the best defenders in the tournament since he joined Wolfsburg from Basel in summer 2011.
An attacking left-back, this season he has netted thee goals and made three assist in just 17 Bundesliga games, underlining his attacking threat.
According to Spanish website TodoMercado the two English sides face competition from Milan to secure the services of Swiss international, who will feature in next summer's World Cup.
Jose Mourinho is looking for a left back as Cole's contract will expire at the end of the year, while Ryan Bertrand has failed to convince the Portuguese that he deserves a place in the Chelsea line-up. Mourinho has preferred to deploy right-back Cesar Azpilicueta on the left so far this season and the signing of a left-back will be a must next summer.
Manchester United are also trying to sign a left-back after the last transfer window, when they failed to secure Leighton Baines and Real Madrid defender Fabio Coentrao. Lately David Moyes' side have also been linked with Brazilian Marcelo and with Southampton youngster Luke Shaw.
Rodriguez is 21 years old and his contract with the German club runs out in June 2016.
His agent Gianluca Di Domenico recently played down his exit in this transfer window but he admits that next summer Wolfburg may consider selling him for a lucrative offer.
"In January, he will not move from Wolfsburg because the club does not want to sell as they absolutely want to get into the Champions League," Domenico said.
"Maybe after the World Cup in June [he can leave] but it will not be easy for Milan as many clubs are interested in him."