Though on paper the fixture looks like a formality for Arsene Wenger's men, the former AC Milan player pointed to last season as a reminder to why if any competition should be approached with caution, it's the FA Cup.
The Gunners met Wigan in the semis last year, with the Latics also defending champs despite being relegated the year before. They had beaten Manchester City in the 2013 final, and were leading for much of the match against Arsenal.
The Londoners needed Per Mertesacker to come to their rescue with a goal in the last eight minutes of the game, before winning the tie on penalties.
“Wigan definitely [gave us a warning last year] which is why we know exactly what to expect,” the Frenchman told the Arsenal website. “The FA Cup is a very tough challenge and you have to give everything to win it.
“We know it’s never easy to win a trophy and we are very focused. It won’t be easy because we will play a very good team, but let’s start with the semi-final, let’s do the job properly and hopefully we will win it again this year."
Reading are 18th in the Championship and have had a relatively comfortable run to the semi-finals, having avoided any Premier League opposition, but the Royals did net an impressive win over promotion hopefuls Derby County in the fifth round, and have been drawn away from home in every round.
They are without a league win in six games, yet are likely safe from relegation to League One, meaning they can concentrate wholly on the FA Cup semi.
Nevertheless, anything but an Arsenal win would be a huge shock, and Flamini and his teammates should be confident but not arrogant on their short trip to Wembley, having won their last eight league games.