Chris Smalling has identified the two toughest players he has ever come up against.

In a Q&A with Reds fans on Facebook and WeChat, the United centre-half was asked who are the best strikers he has played on during his career.

Smalling was quick to analyse the query, coming up with two of the best attackers the Premier League has ever laid eyes upon.

"Tough one! When I was at Fulham, probably Didier Drogba in his prime – he was a real handful!" said the 25-year-old.

"Obviously he was big and strong when I played against him last year, but he also had that pace at the time as well.

"I think Sergio Aguero is another, with his movement. Drogba is strong and can pin you, but Aguero really doesn't like to get close to you, so as a centre-back you're quite worried because you like to feel them and know where they are.

"He often plays on the shoulder, so it can be quite difficult."