Tesla's strong brand name gives it the opportunity to fix its internal issues, but it's got to do it soon, Roger McNamee told CNBC on Thursday.

"They've built this incredible brand, and yet, now they've got all these people interested in the product, they're creating all kinds of trouble for themselves," said McNamee, a venture capitalist turned Silicon Valley critic. "The brand creates the opportunity to fix the manufacturing issues, but at some point they've got to do that."

Tesla missed Wall Street estimates in its second-quarter earnings update, sending shares of the electric auto maker down 14% on Thursday afternoon. The company did reaffirm its full-year delivery guidance, saying it expects to sell 360,000 to 400,000 vehicles this year.

Investors also took note of another high-level departure at Tesla. CEO Elon Musk announced the departure of its Chief Technology Officer, JB Straubel, on Wednesday. It's the latest in a slew of people leaving the company, with Steve McManus, Michael Schwekutsch, Felicia Mayo and Peter Hochholdinger all leaving in the past year.

"[Musk's] announcement doesn't read well at all," McNamee said. "The departure of the CTO is very poorly timed."

Former Tesla board member Steve Westly remained bullish on the automaker, despite it coming short on revenue and having wider-than-expected losses.

However, he did acknowledge the departures of high-profile executives as something that hurt the company, and he called for more stability.

"It's a blow for the company to lose JB Straubel," Westly said Thursday. "Tesla is doing a lot of the right things, but they need to stabilize the senior management team."

"Steve Jobs wasn't easy to work for," he said. "But you wouldn't want to bet against him."

McNamee says the automaker needs to focus on improving its manufacturing.

"They haven't solved job one of being a car company," McNamee said on "Squawk Alley."

McNamee has previously warned that Tesla needed to become better at the basics, saying it needs to grow in areas such as manufacturing and forecasting if it wants to "survive" as an auto company.

"These are really hard engineering businesses that require tremendous discipline," McNamee told CNBC on July 3. "Tesla is getting there but it's getting there in a way that causes investors a lot of heartburn."

Tesla did not immediately respond to CNBC's request for comment on Westly's and McNamee's statements.