Bottas was quickest in both practice sessions at the Yas Marina Circuit on Friday, but will start Sunday's race at the back of the grid, having brought a fresh Mercedes engine to Abu Dhabi.
While putting together long-run simulations, he made a last-gasp lunge up the inside of Grosjean, who turned sharply into the corner, having seemingly not seen the Mercedes in his mirrors.
The Finn was given a reprimand over the incident, with the stewards noting: "Valtteri accepted responsibility for the collision and acknowledged that it was a failed attempt at an overtake which resulted in the collision."
Bottas said he had anticipated Grosjean spotting him, as Pierre Gasly had done a few laps earlier in a similar incident.
"End of FP2 was a bit compromised with a minor crash," Bottas told Sky Sports, before his punishment was meted out.
"He didn't really see me coming up the inside so it's obviously my apologies, but there was nowhere for me to disappear.
"I went for the overtake and that was it. I thought he was aware I was there and maybe he didn’t look in the mirror before turning in. I expected him to see me and I saw the gap decreasing and there was no escape."
GPFans is a multi-platform, multi-language brand dedicated to Formula One coverage. We bring you all the ins and outs of the sport, 24/7, everything from up-to-the-minute news and features to the latest viral stories and clips.
We believe that a new generation of exciting, outspoken drivers will make F1 more popular than ever before, and we want to give our users access to as much of their heroes as possible, on and off the track. From Lewis Hamilton to Max Verstappen, Daniel Ricciardo to Sebastian Vettel, we provide in-depth analysis of every every Grand Prix in the season, from Australia to Abu Dhabi.
With Formula One under the new ownership of Liberty Media, how the sport is being covered is evolving, and GPFans will look to be at the heart of this progression into new media, as one of the fastest-growing sites covering the king of motorsports.