Marcus Rashford's transition into senior football over the past eight or nine months has been a joy to watch.
The Manchester United youngster has gone from Red Devils youth product to England squad regular, and had more goals (12) in his first 25 senior games than the likes of Lionel Messi, Luis Suarez or Thierry Henry.
However, whilst it has all appeared so easy for the 19-year-old striker, there have been times when he hasn't had it all his own way. And, speaking in a 'Football & Me' feature on United's Facebook page, Rashford has revealed which opponents has been the toughest he has faced so far.
Although the young England forward has played less than 40 games at senior level for club and country since debuting for United back in February, he has still pitted his wits against some of the best in the business.
Indeed, appearances against the likes of Manchester City, Arsenal, Spurs and Everton have seen him come up against some of the best defenders the Premier League has to offer.
But, selecting his ultimate opponent thus far, Rashford plumped for a Gooner.
"Laurent Koscielny at Arsenal. He was a difficult defender to play against.," the Manchester-born striker explains in the video below...
There's no doubt that Koscielny, as he has proven with performances for France at Euro 2016 and Arsenal so far this season, is an elite defender.
However, Rashford's choice is a little surprising considering his own performance against Koscielny and Arsenal last season.
Making his first Premier League appearance for United, the youngster bagged two goals and supplied another as the Red Devils overcame Arsenal 3-2 in February this year.
If that game produced the toughest opposition centre-back he has faced, then United's future opponents should be very worried.
Mind you, with the Red Devils' next three Premier League fixtures coming against Liverpool and Chelsea, he might have a new answer soon enough.
Rashford's quality has shone through once again this season after a quiet opening couple of weeks.
With Wayne Rooney's form on the decline, the youngster has forced his way into Jose Mourinho's plans earlier than many expected and already has four goals for the Old Trafford club this season.
Add to that the memorable hattrick he scored on his England Under 21 debut recently and you have to think that Rashford himself will soon become the answer to the question; 'Who is the toughest player you've played against'.