The Magpies squad did not speak to journalists after pre-season defeats by Augsburg and Braga. They also declined to take part in filming duties for broadcasters including Sky Sports and BT Sport.
While Lascelles refused the discuss the issue, he said the team was looking forward to delivering positive results on the pitch.
"We've managed to sort the off-field stuff; now that's out of the way, we don't have any reason why we can't go out and put on a good performance," he told the club's website.
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"I think the last game (against Augsburg), we can definitely take a lot of positives from that - okay, we didn't win but we got everything we need out of the game.
"The majority of the team got through (pre-season) injury free and everyone is really fit."
Lascelles was pleased with Newcastle's close-season transfer business and hailed the arrival of striker Salomon Rondon, who joined on a season-long loan deal from former Premier League side West Bromwich Albion.
"Rondon's a very good signing - a very powerful player, fast, strong," he added.
"I didn't play against West Brom away but when we played them at home, in terms of physicality, he's probably one of the toughest strikers I've played against.
"We've made some good signings and I think it won't take long for us to really gel together and carry on with the same team chemistry that we had last year."
(Reporting by Hardik Vyas in Bengaluru; Editing by Christian Radnedge)
