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Here come the players, Theo Walcott is second in line as Arsenal step onto the pitch for a warm up. Per Mertesacker - who scored their crucial equaliser in the semi-final last year - is first out of the tunnel. He cannot wait to get out there, like a dog let off the lead.

It's nice and warm, the huge structure that is Wembley creates a shade over most of the pitch but those players will soon have a sweat on.

It may have the feel of a pending destruction - Premier League in-form side take on Championship outfit, but think on.

The Gunners, chained and hampered by that long run without a trophy at this stage last year, ran into Wigan in the semi-finals and needed and 82nd minute equaliser and penalties to prevail.

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Oh yes, don't go big on too many one-sided predictions here. The FA Cup's last four loves to throw up a ding dong. Have a gander at this feature on semi-final battles if you don't believe me.

Like Richard and Isobel in the previous entry, Reading's supporters have turned up en masse and are flooding Wembley Way as we speak. Try telling them on this day that the home of English football should not host semi-finals.

Image source, Reading FC/Twitter

Nabil Hassan
BBC Sport at Wembley

One fan Reading fan I've spoken to named Richard will be at Wembley with his six-week year-old daughter (Isabel). He had to pay £43 for her seat.

"It's Wembley we don't get there very often, particularly in the FA Cup so she is potentially the only person there who could get to see a another one."

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Without sounding harsh, Reading's FA Cup record is dismal.

The Royals have never played in an FA Cup final in their 144-year history. They did make the semi-finals once but got thumped 3-0 by Cardiff City in 1927.

I guess that makes today very special for several generations of supporters. What may feel like routine, obligation and expected for Arsenal is dream like, raw and undoubtedly nerve-filled for the Championship side.

Former England midfielder Danny Murphy
Football Focus

"Danny Welbeck has played more at Arsenal than he did at Manchester United, and he's had good form even if his goal scoring has not quite been up to the level you'd expect. The fans have taken to him.

"He is very flexible, and his goal at United was such a sweet moment for him. I'm glad he celebrated it. Arsenal have such an array of fantastic attacking players but he is still contributing more than he was at Old Trafford."

A notable omission from the Arsenal XI is Olivier Giroud who has five goals in his last five games. His place on the bench shifts some focus on to Danny Welbeck who will probably play through the middle for Arsenal - his favoured role.

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John Hartson
BBC Radio 5 live

"Reading will play like supermen today, a lot of the players will have not played at Wembley. All the pressure will be on Arsene Wenger and Arsenal. They will be expecting an Arsenal win but will not have an easy ride. Reading and Steve Clarke will be right up for it."

Image source, PA

Reading's players are having a walk on the turf, gazing into the red seats to look for recognisable faces.

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Jordan Obita, at just 21, was keen to take it all in. No goals for him in 46 games this season. Talk about the stuff of dreams if he broke his duck here.

Arsenal, ridiculed for their soft centre at points earlier in the season, are on an eight-game winning streak in the league and the last time they made it to nine, it's fair to say they were a decent side.

An 'Invincible' side no less in 2003-04. Sure Francis Coquelin, Per Mertesacker and Olivier Giroud may not be Martin Keown, Patrick Vieria and Thierry Henry, but it's encouraging for Gunners fans no less.

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"You want to go to the final and get there," says manager Arsene Wenger. "You have to absolutely spot on with everything.

"You can always imagine the consequences of not going (through)... therefore there is only one way, and I have enough experience to know how big this game is."

Image source, Arsenal FC/Twitter

Both the sides have turned up, the usual array of bulky headphones on some players as they bounce down from the bus, through the mixed zone, through the tunnel and either right or left into their respective changing rooms.

Nabil Hassan
BBC Sport at Wembley

"Among the Reading fans strolling down Wembley Way earlier was chairman of 25 years Sir John Madejski who took the opportunity to stop and have his picture taken with several supporters of the Championship club. Nice touch."

Reading fans have been brightening up the cold concrete of Wembley Way from around midday, why make the short journey from London's commuter belt late in the day when you can do it straight after breakfast eh? This is a special day after all.

Our reporter Nabil Hassan is there chatting to many of them and we will bring you some tales from Wembley Way shortly.

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Go on then, let's trot out the 'magic of the cup' cliché for the first time today (I'll wait at least five minutes before going there again).

One man who has been Reading's very own Paul Daniels (Dynamo if you're not yet 25 years of age) in the cup this year is Hal Robson-Kanu.

The 25-year-old has scored three goals in his last four FA Cup appearances this season, despite only scoring one league goal in 28 games.

Former England midfielder Danny Murphy
Football Focus

"Reading have got good pace on the counter, which could work well for them as of course we think Arsenal will dominate possession. In midfield Nathaniel Chalobah has looked good, he's a good passer of the ball, but ultimately the question will be whether Reading can get enough of the ball to cause problems. On a hot afternoon they don't want to be chasing all day.

"But they have got a great opportunity, and why not? Shocks can happen."

Nabil Hassan
BBC Sport at Wembley

"Russian forward Pavel Pogrebnyak has passed a fitness test on his injured calf and starts up front for Reading. Club captain Jem Karacan is on the bench so central defender Alex Pearce takes the armband. He is joined on the bench by veteran striker Yakubu. There's plenty of pace in the Royals midfield with Garath McCleary also included."

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And what better way to start than with some breaking team news, Jack Wilshere is back on the bench for Arsenal having not played since 22 November. Wojciech Szczesny is in goal as his run in cup games continues and Mathieu Debuchy is in at right-back, his first appearance since 11 January.

Arsenal: Szczesny, Debuchy, Gibbs, Mertesacker, Koscielny, Ozil, Ramsey, Alexis, Cazorla, Welbeck, Coquelin.

Reading: Federici, Gunter, Pearce, Pogrebnyak, Robson-Kanu, Obita, Chalobah, McCleary, Mackie, Williams, Hector.

Welcome to FA Cup semi-final day one of two. It's Wembley, it's a team given little hope against the side who lifted this trophy last season.

Reading are the David, Arsenal the Goliath, but this competition loves nothing more than splattering egg on the face of those who should ordinarily have things their way.

We have colour from Wembley way coming up, team news, stats, a social media debate, images, hopefully goals and who knows, maybe even a giant killing.

"The team with the best players don't always win a semi-final. It's a one-off. Sometimes character, determination, guts and passion are more important than skill." - Crystal Palace manager Steve Coppell after his side rumbled Liverpool at this stage in 1990.

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There's a Rolls Royce on its way to a spring meeting where only the best are welcome.

The roof is down, it shimmers, gleams and oozes quality, it's been looking immaculate since winter disappeared.

It's driver, an aristocrat in his field, moves along in his slick white shirt, he has the cut of a man of experience, he's worked for days like this.

But something is in his way.

A pot hole. A nuisance battered by a winter spent in rugged surroundings stubbornly sits in the middle of the road.

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