Manchester United defender has jokingly questioned the validity of Scott McTominay's "unbelievable" 5km time, stating he "doesn't even know if it's real".
With the current UK lockdown measures allowing just one hour of outdoor exercise each day, the nation has taken to running - and the 5km challenge has become popular with people running 5km, donating £5 to the NHS 'Run for Heroes' campaign, and nominating five more people over social media.
Where many are breaking that 25-minute boundary for the first time, McTominay posted a lighting-fast time of just 16 minutes and one second.
The Sun subsequently reported the United midfielder to have overrun by 30 metres, meaning - without the extra distance - his time would have actually been 15 minutes and 45 seconds.
Only the top 27 runners this year have recorded a quicker time than that - though it appears as though the midfielder's time was spread across intervals, rather than one single run, which would make his time slightly less impressive.
Nonethless, United team-mate Shaw is impressed, telling the club's website: "[The] fitness challenges set by the coaches have been really good for the United lads.
"Naturally, we all get quite competitive over them. Scotty posted his 5km time on social media last week, which was a joke, something like 16 minutes. I don’t even know if it’s real.
"Harry [Maguire] did one today at 18 minutes, which is a really good time, but Scotty is a joke.
"He’s one of the fittest in the team and, if I’m not wrong, I think his dad was a runner. He must be giving him tips and training him up at the moment.
"It’s unbelievable how fast that time is. When I saw it, I put it into the treadmill to check the speed, and it was some ridiculous level, just a flat-out sprint, for 5km. Unbelievable.
"He’s a big, tall lad though, so maybe his big stride had something to do with it, but he’s a machine. Jesse too, actually. Those two are setting the benchmark that everybody needs to get to."
