Lewis Hamilton has seen Formula One title rival Sebastian Vettel open the season with two straight wins, but Sunday's Chinese Grand Prix offers the Briton an ideal opportunity to fire up his challenge with a maiden win of the year.
While he put no blame on Verstappen's shoulders, insisting that's the sort of risk-reward nature he loves about the Dutchman, Horner said there was need for a "good chat" to ensure Red Bull capitalise on their race pace.
"We got it better for practice two and that way lap times were improving".
Verstappen also said that the light rain that came late in Free Practice 2 did not harm Red Bull's programme for the day, believing that the RB14's long run pace is promising. "It happened to us a year ago the other way around", he added. "We all need everyone to be on it all weekend because it's a joint effort".
The world champion ended the session 0.359 seconds quicker than Kimi Raikkonen, despite using harder tyres.
Vettel, 17 points clear of Hamilton following victories in Australia and last week's Bahrain Grand Prix, was only sixth.
Hamilton has won five of the last 10 races in Shanghai but thinks the track will suit Ferrari, whose driver Sebastian Vettel has won both races so far in 2018.More news: Strikes against Syria could begin as early as Thursday night: Report
The lap-times in the second session were a lot closer, however, after Hamilton went comfortably fastest in the morning, raising hopes for a closely-fought race with Red Bull also showing flashes of speed.
Verstappen clipped the apex at the last bend and slid off into the gravel. So just as we were signing just now I shook his hand and I was like "look, I'm sorry about the last race".
Haas were best of the rest, with Kevin Magnussen seventh and Romain Grosjean ninth split by Renault's Carlos Sainz, whose team-mate Nico Hulkenberg was 10th.
McLaren's Fernando Alonso completed the top 10 ahead of the Force India of Sergio Perez and Pierre Gasly's Toro Rosso.
The only man to see his session end early was Stoffel Vandoorne, who had to pull his McLaren over with a suspected loose right-rear wheel after a pit stop. And Williams look no closer to solving their early season problems, with Lance Stroll finishing at the bottom of the pile in both sessions.
The Canadian, having gone slowest in the opening session, continued to prop up the timesheets in the afternoon.
"I think overall if you take into account all the testing we did et cetera, then Mercedes is still the favourite going in".