Houston worked with the Bairns first-team coach during his time with Hearts and the pair have remained close ever since.
Pressley was made a member of Falkirk manager Eddie May's coaching team in the summer and Houston, who assisted Craig Levein for nearly a decade, was on hand to offer words of wisdom.
But after Houston's United suffered a 7-1 Scottish Premier League humiliation at the hands of Rangers last month, Pressley was the one picking up the phone.
With their teams in direct competition on Sunday, the pair have not spoken this week and Houston hopes his players do their talking on the park.
He said: "Funnily enough, I haven't heard from 'Elvis' this week. He phones me just about every other week.
"Even if I tried to phone him he would have blanked me because he's very professional that way.
"I like him and at the start of the season I was giving him a few rings because they were going through a bit of a sticky spell.
"I always thought he'd go onto be a really top coach but it's always difficult if you're getting beaten.
"Then I got a phone call from him the day after we lost 7-1 to Rangers at Ibrox - but I blanked it.
"It was nice of him to phone me after Ibrox as he was obviously showing his concern but I just couldn't face speaking to him.
"I'll see him again this weekend but my main focus is Dundee United and trying to keep our run going."
United look like a team transformed now the players are over the shock of Levein leaving to become Scotland manager.
The heavy defeat at Ibrox was followed by a home loss to Aberdeen but since then they have won three matches on the bounce, beating Partick Thistle, Hamilton and Hibs.
Houston, who will remain in charge as caretaker until chairman Stephen Thompson finds a permanent replacement, now sees a group of players brimming with confidence and revealed he has even had to tell them to ease off in training.
He said: "Victories have given the players confidence so I just sense that Sunday can't come quickly enough.
"I had to hold them back am little bit in training which is always a good sign.
"They were going at it full pelt but sometimes you just have to save your energy in the build up to the game."
Source: Team Talk