The defending three-time world champion dominated the session while the German, who holds an 11 points lead over him in this year's title race, was left on the sidelines as his auto was dismantled for repairs in the team garage.
British Formula One driver Lewis Hamilton (Mercedes) was the fastest in the first free practice for the British Grand Prix at Silverstone here on Friday.
But yesterday the threat was lifted with Mercedes stating: "As passionate racers, we want to see them racing, and so do the fans of Formula One".
The Spielberg collision was the fifth coming together between the pair, and the third in five races.
For Jenson Button, the 2009 world championship, this could yet be his last British Grand Prix.
"It's a shame that I wasn't able to have a run in the afternoon - but I'm sure we can fix the problems by tomorrow morning", said Rosberg. It's not that we are best friends.
"By the time we go into FP3, Nico will get quickly up to speed and tune himself in before qualifying", Lowe said.
"The auto is definitely feeling good, but we've definitely got some work to do with the balance", he reported, "What is really hard is to pinpoint exactly where the target is from corner to corner - because of the wind, the target is moving everywhere". If Toto Wolff (the Mercedes team principal) told me what to do, I would look at him and laugh.
Reflecting on the statement, Hamilton, 31, added: "Unfortunately the damage was already done".
Asked by Sky F1 what could stop him wining Sunday's race, Rosberg replied: "Lewis Hamilton is the only possibility at the moment".
The drivers have been warned that they may be issued with instructions during races to protect points in the constructors' championship, but the precise details of the "rules of engagement" were not explained.