This is not good news for CEO Meg Whitman, who joined HP’s (HPQ) board in January 2011 and became CEO that same year in September. Despite the nearly $9 billion write-down of HP’s Autonomy purchase in November 2012 and lingering concerns about HP’s business model and strategy on her watch, Whitman has survived atop HP much longer than her predecessor Leo Apotheker did. (He served less than a full year.)

Her survival has been aided in large part by Whitworth’s evident patience and support since he joined the board in November 2011 and then became interim chair in April of last year. Whitman has benefited from the respect other shareholders have for Whitworth—and his presence and optimism have reassured HP shareholders about the company’s course, keeping them at bay. The mutual respect between the CEO and chair was evident in their statements in the tech giant’s press release announcing Whitworth’s departure.

Former J.C. Penney (JCP) CEO Ron Johnson likely wishes he’d had Whitman’s situation. In his case, shareholder activist Bill Ackman, who served on the J.C. Penney board, had recommended the former Apple executive for the top spot at the retailer. But Johnson was out the door in less than two years. Patience had run out.

“Ralph was a big asset to corporate governance at HP,” says John M. Nash, founder and president emeritus of the National Association of Corporate Directors. When Whitworth was president of the United Shareholders Association, Nash and Whitworth used to spar on TV about governance issues, Nash says. “We agreed to disagree and we always respected each others’ opinions,” Nash told me. (Full disclosure: Nash has worked with my company.)

HP’s latest voting materials described some of the firm’s accomplishments during Whitworth’s tenure. The company was one of the first to allow shareholder nominated directors, under certain conditions, to be included in the company’s official voting materials. In July 2013, the company hired three new directors. And the board expanded its outreach to shareholders on Whitworth’s watch.

HP had a lot to do to rehabilitate its governance image. Today, HP is no longer the laughing stock it once was in the corporate director community.

It will be difficult for HP’s board to continue effectively in Whitworth’s absence. When Whitworth was appointed as interim chair in April 2013, I wrote that, “Whitworth has pledged that the board will recruit a chair presumably outside the ranks of existing members.” In July 2013, three new directors joined the board. But none have governance running through their veins, like Whitworth has, and none would provide the shield from shareholders that CEO Whitman has enjoyed. As of February 2014, the board reported that it was still searching for a suitable chair candidate.

Giving the chair role to Whitman now would be a big mistake for HP, the board, and Whitman herself. But it’s possible the board will make that mistake. While the shareholder voting materials earlier this year said that, “The Board’s preferred governance structure is to separate the roles of Chairman and CEO because it allows our CEO to focus primarily on our business strategy and operations,” later on, the same document equivocates. “This reflects the Board’s preferred governance structure of a separate Chairman and CEO, but the Board’s leadership structure may vary in the future as circumstances warrant.”

HP has many challenges ahead. At the end of June, HP had good news on the Autonomy front when it reached settlements in three shareholder lawsuits, the Wall Street Journal reported. But, as the Journal pointed out, regulatory inquiries are ongoing. Apple’s (AAPL) new partnership with IBM (IBM) is just one example of a host of competitive struggles the company faces.

Relational, Whitworth’s firm, has been a major owner in HP stock. If the board is smart, they will consider extending an offer to Dave Batchelder, Relational’s other co-founder, to join the board and take the interim chair spot until a permanent chair is selected. Batchelder, like Whitworth, is respected in both the shareholder and board member communities. He could stabilize the board and help ensure HP finds the right permanent chair.

Such a move would also give Whitman more time to focus on her responsibilities as CEO of HP. I’m thinking she could use it.

Eleanor Bloxham is CEO of The Value Alliance and Corporate Governance Alliance, a board education and advisory firm. She may be reached at ebloxham@thevaluealliance.com.