Chelsea will match any bid from Manchester City to acquire Ross Barkley next summer.
Chelsea were interested in Barkley even before he broke out for Everton last season.
Everton signed Barkley to a long-term deal this past summer.
Barkley valuation reportedly increased to €64 million following early-summer interest from Manchester United.
City would love to acquire Barkley to increase their "homegrown" quota.
Chelsea hope that they have a trump card in the shape of senior international scout Mick Doherty.
Doherty spent seven years with Everton up until 2011 and enjoyed a good relationship with Barkley, who was coming through the ranks at the time.