Morgan Stanley believes the size of Tesla's U.S. workforce may become a big factor affecting the company's long-term survival.

The firm's analyst Adam Jonas noted Tesla employed 37,543 workers at the end of last year and predicted the number will increase to nearly 50,000 by 2019 or 2020.

"Tesla may be more on the 'too big to fail' spectrum than the market realizes ... the vast majority of [the company's workforce is] in the United States, and across many states," he wrote in a note to clients Wednesday. "Rule of thumb on the economic multiplier says that one auto-related job can support as many as seven other jobs throughout the economy."

The U.S. government bailed out GM and Chrysler during the financial crisis, in part because of their large employee bases.

Jonas lowered his price target to $376 from $379 for Tesla shares, representing 31 percent upside to Tuesday's close. He reiterated his equal-weight rating for the stock.

The analyst also raised the stakes for Tesla shareholders, saying the developments over the next few months could move the stock significantly up or down.

"We see the next three months as the most critical time in Tesla's history since the Model S launch six years ago. The fundamental pendulum could move in either direction or in both directions in a big way, making Tesla the ultimate high risk name in autos," he wrote in the report entitled "Tesla's Next Move: $200 or $400?"

Although Telsa stated it doesn't need to raise capital this year, the analyst expects the company will raise $2.5 billion in its third quarter through a stock sale. Jonas noted the investor community is still skeptical of the car maker's Model 3 production targets.

"No investor that we have spoken to expects Model 3 production of 5k/week by the end of 2Q'18," he wrote. "We don't expect a 5k/week run-rate to be achieved before late 4Q'18."

Tesla shares rose 2 percent Wednesday, a day after Elon Musk sent an email to Telsa employees setting a new internal goal of 6,000 Model 3 vehicles per week by the end of June.