The Swede had four bogeys and one birdie over the first nine holes at Torrey Pines. From the 11th to the 15th holes, he had five straight bogeys.
The last two holes were birdies, which somewhat salvaged the 26-year-old's round. But with nine bogeys, it is Åberg's worst result on tour in his career, according to Expressen.
The Eslöv native stood at +6 after 18 holes. Åberg had to withdraw from last weekend's season opener due to illness.
Alex Norén also had a weak round and finished three over par. Henrik Norlander was the best Swede in 87th place.
Englishman Justin Rose leads the tournament at ten under par.
