Day was seen running from the match at Rodney Parade to get to the Royal Gwent Hospital on Tuesday evening.
He said: "Knowing how good Pep is I'm sure they'll overcome that pitch".
Newport will be the lowest-ranked side Guardiola has faced in his three seasons at Manchester City, but Flynn can take heart from last year's FA Cup, when League One Wigan beat the Premier League champions in the fifth round.
Robbie Willmott and Padraig Amond scored brilliant second-half goals for the Welsh side to secure a plum tie at home to Pep Guardiola's side on February 16. "We can play like that, but not every week in League Two".
Wilmott was the provider as he whizzed in a risky ball for the 30-year-old to smash past Greek shot-stopper Dimitrios Konstantopoulos.
I said, 'Of course you can.
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Sprint dubbed its short-lived WiMax network 4G, while T-Mobile and AT&T blurred the lines by calling advanced 3G a flavor of 4G. However, for many users who do not understand technology, they will mistakenly believe that AT&T has provided the 5G network.
He sprinted off, it's the quickest I've seen him move, but all our thoughts are with Joe and Lizzy and the arrival of the twins.
Elsewhere, Ivan Cavaleiro's victor spared Wolves' blushes after the Premier League side came from 2-1 down to beat League One Shrewsbury 3-2 at Molineux.
Ivan Cavaleiro then completed the Wolves comeback in the second half.
"I think we should try and get a couple (of rugby fixtures) on there".
Brentford will travel to Swansea City for an all-Championship clash after seeing off non-league outfit Barnet 3-1.