NORTON, 5 Sept 2015, (AFP) - It was the first time in his young career that the 22-year-old Spieth has missed back-to-back cuts on the USPGA Tour.
"It is almost like a bad dream," said Spieth, who added he is going to take a few days off after Saturday's disappointing round.
Spieth had bogeys on three of his final six holes as he finished 36 holes at six-over 148.
Charley Hoffman was the 36-hole leader on 130.
It was just the fourth missed cut of the season for Spieth who was seeking to rebound this week after failing to get into the weekend action last week at The Barclays in New Jersey.
The American's two week stint as world number one came to an abrupt end at The Barclays, with Rory McIlroy regaining the top spot even though he didn't play last week.
Spieth had toppled McIlroy from the number one ranking three weeks ago with a runner-up finish to Jason Day at the PGA Championship.
Leading second-round scores on Saturday in the $8.25 million US PGA Tour Deutsche Bank Championship (Par 71, USA unless noted):
130 - Charley Hoffman 67-63
133 - Brendon de Jonge (ZIM) 65-68
134 - Kevin Chappell 67-67, Matt Jones (AUS) 67-67, Rickie Fowler 67-67, Zach Johnson 69-65
135 - Sean O'Hair 68-67, Russell Knox (SCO) 70-65, Henrik Stenson (SWE) 67-68
136 - Danny Lee (NZL) 70-66, Jim Furyk 71-65, Hideki Matsuyama (JPN) 71-65, Jason Day (AUS) 68-68
137 - Daniel Berger 68-69, Brendan Steele 70-67, Jerry Kelly 71-66, Keegan Bradley 71-66
138 - Hudson Swafford 69-69, Gary Woodland 68-70, Luke Donald (ENG) 67-71
139 - Ian Poulter (ENG) 67-72, Daniel Summerhays 71-68, Patrick Reed 72-67, Bae Sang-Moon (KOR) 69-70, Jason Dufner 69-70, Zac Blair 70-69
140 - Louis Oosthuizen (RSA) 73-67, Kevin Na 72-68, Dustin Johnson 70-70, Alex Cejka (GER) 70-70, Brian Harman 70-70, Charles Howell 70-70, Colt Knost 67-73