Although Marquez moved four points closer to the top by again finishing ahead of Rossi, he lost points to race winner Lorenzo for the first time since Catalunya in mid-June.
And with Lorenzo tied with team-mate Rossi at the head of the standings, Marquez must now beat both Yamaha riders this weekend at Silverstone if he is to make any championship ground.
“Brno was a difficult weekend but we took important points in the Championship and keep fighting!” said Marquez, the title winner in both his previous MotoGP seasons.
“Silverstone isn’t one of my favourite tracks but I enjoy going there as you can feel the excitement and the history that surrounds the circuit and the area as a whole.”
Marquez beat Lorenzo by 0.7s at Silverstone last season, having lost out to his fellow Spaniard by just 0.081s the previous year.
“I’ve been on the podium there the past three years including a win last year, so let’s hope the weather is good to us and we can fight for a similar result this year.”
A foot injury for team-mate Dani Pedrosa at Brno meant the #26 was unable to threaten the Movistar Yamahas.
“It wasn’t our best weekend in the Czech Republic but we were able to fight our way up to fifth and we must learn from the experience,” Pedrosa said. “My ankle is feeling much better now – not 100% – but I’m not in as much pain as I was in Brno.
“Silverstone is a very fast track, it’s very flat – being an old airfield – and it has many changes of direction, so finding a setup that suits both the fast and slow corners is the challenge. As always, the British weather is the unknown factor so it’s important to keep an eye on that!”