He notched the fifth fastest time in his semi-final in Rome, running 10.05 secs.
“If I think that I didn’t make the final for only four one hundredths, I’m a little bit miffed,” he said.
Jacobs also said he was surprised that reigning world champ Fred Kerley of the US, who came second to the Italian in Tokyo, had also been eliminated.
The first two in each semi plus the two best times go into the final, so it is impossible for Jacobs to get a recall.
The 28-year-old El Paso born runner, who also won gold as part of Italy’s 4x100 relay team in Tokyo, has only recently returned to competition after a string of injury layoffs.
He said he knew it was going to be hard to improve on his recent form, but that it was important to try anyway.
“Today it went much better than yesterday, I knew it wasn’t easy.
“I put everything I had into it, but I hadn’t competed enough recently,” Jacobs said following the race.
“I could have stayed at home but I decided to have a go. I’m not afraid of getting beaten and I know that this is not my real time.
“Now [it’s] all systems go for the relay.
“Spending so much time without competing and then doing the worlds wasn’t easy, but I go back to my hotel satisfied even though I wanted to get into the final for a title I know can be mine.
ANSA