Jose Mourinho certainly made his mark in the transfer window after arriving at Manchester United.He smashed the world record transfer fee to sign Paul Pogba for £89 million, brought Henrikh Mkhitaryan from Borussia Dortmund for £26.3 million and snapped up Zlatan Ibrahimovic on a free transfer.Three very exciting signings.But there was a fourth signing - Eric Bailly.Bailly arrived as a relatively unknown defender and Mourinho hardly excited the fans when he admitted the youngster may not be ready for first-team football immediately.But the Ivorian has proved the Portuguese boss wrong by adapting to English football impressively and becoming an important member of United’s backline.One attribute that has helped Bailly settle in so quickly at Old Trafford is his searing pace. The former Villarreal man has the speed to match any attacker and is extremely difficult to beat in a race.And he showed that once again against Anderlecht.United needed extra-time to overcome their Belgian opponents after drawing 1-1 in 90 minutes at Old Trafford.Towards the end of the game, though, Mourinho’s side were pushing for the winner to prevent extra-time and they had to be wary of Anderlecht impressive counter-attack.At one point, winger Frank Acheampong thought he had the perfect chance to expose United with just eight minutes remaining of normal time.Acheampong - who has 92 rating for acceleration and 91 rating for sprint speed on FIFA 17 - must have fancied his chances when one-on-one with Bailly.But he soon realised his mistake when he attempted to knock the ball past the United defender. Despite being regarded as a nippy winger, Acheampong was no match for Bailly who easily outpaced him to pass the ball back to Sergio Romero.Acheampong then collapsed to the ground, seemingly complaining of cramp.

Bailly's pace

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And there were plenty of United fans that noticed Bailly’s incredible pace on Twitter during the match.

United fans reacted

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Mourinho will be hoping that Bailly can continue his impressive debut season and help the club complete a double by winning the Europa League to add to the EFL Cup they have already won.

With Phil Jones and Chris Smalling currently sidelined, and Marcos Rojo picking up a serious looking injury against Anderlecht, Bailly will be even more important for the team in the coming weeks.

But a warning to any forwards facing Bailly: don’t try and outpace him.