This month, Tesla said that issues with , but the hiccups have caused a months-long delay to the automaker’s manufacturing schedule for 2018. Now two high-ranking employees involved with launching the Model 3 line left the company in recent weeks, Jalopnik has learned.

Jason Mendez, who joined Tesla back in 2005, worked an array of jobs at the company, most recently as senior director for manufacturing engineering, according to his LinkedIn profile. Mendez didn’t respond to a request for comment.

Tesla said on Wednesday that it made “major progress” addressing bottlenecks in the Model 3…

Along with Mendez, Will McColl, a former senior manager for equipment engineering, has also left the company. McColl couldn’t be immediately reached for comment, but he confirmed his departure on LinkedIn, saying he resigned from Tesla earlier this month.

“It was an action-packed 7 years of automation equipment design and I will truly miss the team,” McColl wrote. “I will treasure our countless moments of laughter as we fearlessly dismantled the edifice of ‘impossible!’”

A source familiar with the matter said both Mendez and Kroll were involved in the automation of the Model 3 production line, as well as the integration of German supplier Grohmann Automation, . Another source confirmed the two aren’t listed anymore in the company’s employee directory.

The circumstance of their departures isn’t immediately clear—Tesla has said —nor if they’re connected to the Model 3 issues.

Tesla declined to comment.

“I’m continually inspired by my colleagues’ resolve,” McColl said on LinkedIn, “and I wish them strength as they ramp and refine Model 3. It’s an amazing car!”

McColl said in his post on LinkedIn that he’s planning to move home from Germany in the coming months.

“Stay tuned!” he wrote.

Tesla launched production of the Model 3 in July, but the manufacturing process got off to a sluggish start. The company reported it produced only 260 Model 3s in the third quarter of 2017, far short of its goal. , and pushed back a target of production 5,000 Model 3s per week by the end of 2017 to late March 2018.

Tesla reported making 2,425 Model 3s in the final quarter of 2017, and said that the production rate increased “significantly” in December. But then the company said it had to again push back the 5,000-per-week target to this summer.

“As we continue to focus on quality and efficiency rather than simply pushing for the highest possible volume in the shortest period of time, we expect to have a slightly more gradual ramp through Q1, likely ending the quarter at a weekly rate of about 2,500 Model 3 vehicles,” Tesla . “We intend to achieve the 5,000 per week milestone by the end of Q2.”

Tesla has since started deliveries of the all-electric sedan, which starts at $35,000, to early customers. The company previously said it has about 450,000 Model 3 reservations.

Editor’s Note: The headline of this article has been changed to clarify that there is no immediate evidence tying the two departures directly to Model 3 production issues.