The Blues got their Premier League campaign off to the best possible start on Sunday, comfortably beating Wigan 2-0, whilst Brian McDermott's men earned a point against Stoke City through a late penalty the day before.
And Di Matteo declared that his side will approach their meeting with the Royals with the utmost professionalism.
"I'm very wary of newly promoted teams like Reading and Southampton," he told the club's official website.
|6/1||Chelsea are 6/1 with Bet365 to beat Reading 1-0
"It's going to be a very difficult game when you play a newly promoted team early on, full of enthusiasm and spirit. We will try our best to win our first home game.
"You sometimes look at it and think you don't want to change a winning team but it doesn't always work like that. We will see for tomorrow night - I haven't made my decision yet. We finished training not long ago and I have to think about it."Despite Florent Malouda and Yossi Benayoun's absences from the squad against the Latics, the Swiss-born boss remained non-committal on the pair's futures at Stamford Bridge.
"At the moment it's just a selection issue. We have a lot of competition and a lot of players in certain areas. That's what it is at the moment, a fight for places," he continued.
"I tend to speak to all the players. We have conversations and they are Chelsea players and part of the squad at the moment.
"We will have to see, but until the transfer window closes they are with us and they are part of it."