The 25-year-old has only recently returned from injury and could start against Man United on Sunday at Stamford Bridge, where Rangnick will no doubt catch a good glimpse of his former protege.
While his goal return since arriving in England leaves something to be desired, Werner is an unselfish runner off the ball and works tirelessly in helping press high up the pitch. Even if his finishing needs work, his pace and work rate are attributes that would be appreciated by his compatriot Rangnick.
Werner has spoken in glowing terms about the effect his former boss had on his career, helping him focus on his game and block out any outside noise during a difficult period in his career.
The forward spent time working under his guidance when the pair were at German club RB Leipzig, with Werner leading the line and Rangnick a sporting director before becoming manager.