Lewandowski forged a fruitful partnership with Shinji Kagawa in Dortmund's 2011/12 season as the pair helped Dortmund retain the Bundesliga and win it for a second time in a row. The duo managed 47 goals between them that season - Kagawa managing 17 and Lewandowski plundering 30 more. That total is just three less than what United's strike force have managed so far this season. Of course, Kagawa joined United from Dortmund last summer, and fans must be relishing the prospect of the duo linking up at Old Trafford and repeating that sort of cohesive understanding on the pitch. If Kagawa and Lewandowski can rekindle their devastating partnership, United's rivals will be in serious trouble.