Bouchard's exit continues her dismal run of form this year, which started with her second round loss to Mona Barthel at the WTA BNP Paribas Diamond Games in Belgium in February.
The Canadian has enjoyed little success during the clay-court season, losing to Barbora Strycova in the first round of the Mutua Madrid Open and Carlo Suarez Navarro in the third round of the Rome Masters.
"About today, I mean, honestly, I don't know what to say," she told reporters after the match. "I felt I was in the match. But tennis-wise, I still knew I was far off from how well I can play. But, you know, I was in there. It's been kind of the same as how I have been feeling recently on the court. Just not like myself.
"I have been trying to work on what's been going wrong, and I feel like I've been making progress, so to still have matches like this is disappointing. But at the same time it's just a tennis match – life is still good, everyone has highs and lows in their careers, and this is just a little bit of a low point for me."
The 21-year-old is now hoping to kickstart her year during the grass-court season and mirror her results at Wimbledon last year, where she became the first Canadian player to reach a Grand Slam final.
"Hopefully the grass will be good for me," she said. "Plans are to go and play a couple of warm-up tournaments."