Federal Reserve Chair Janet Yellen's speech on Friday on running a "high pressure" economy with a tight labor market to reverse some of the negative effects of the Great Recession of 2008 suggests the U.S. central bank will stay accommodative for longer, according to Jeffrey Gundlach, chief executive of DoubleLine Capital.

"I didn't hear, 'We are going to tighten in December,'" Gundlach said in a telephone interview. "I think she is concerned about the trend of economic growth. GDP is not doing what they want."

Gundlach, who oversees more than $106 billion at Los Angeles-based DoubleLine, said the GDP Now indicator from the Atlanta Federal Reserve has been cut in half to 1.9 percent for the third quarter, after only 1.1 percent actual growth for the first half of this year.

"GDP Now keeps fading away," he said. "If we get only 1.9 percent GDP for third - and fourth quarters - we are looking at only 1.5 percent GDP this year."

Gundlach said Yellen's remarks suggest that she embraces the hypothesis introduced by former U.S. Treasury Secretary Larry Summers, who said secular stagnation, or a lack of demand, is pushing down global growth.

Yellen said there are "plausible ways" that running the U.S. economy hot for a while could fix some of the damage caused to growth trends by the Great Recession. In her speech to a Boston Fed conference on Friday, she said that increased business sales would "almost certainly" help boost the economy. "A tight labor market might draw in potential workers who would otherwise sit on the sidelines," she said.

Gundlach said he read Yellen as saying, "'You don't have to tighten policy just because inflation goes to over 2 percent.'

"Inflation can go to 3 percent, if the Fed thinks this is temporary," he said. "Yellen is thinking independently and willing to act on what she thinks."

Gundlach said Yellen's remarks "are in the same range" of European Central Bank President Mario Draghi's 'Do whatever it takes' speech in 2012.

Gundlach noted the long-end of the yield curve "hated" Yellen's remarks, because they suggest the Fed would allow inflation to run beyond the 2 percent level.

With the 10-year Treasury note now at a yield of 1.80 percent, which is up 48 basis points since early July, Gundlach said he is less bearish on government bonds.

"I'm still defensive but one notch less than maximum negative on Treasuries," he said, noting that the yields on Treasury bills, notes and bonds are now above their 200-day moving averages.