By Glen Andrews and Gary Smith, World-Track
Steve Cram believes Asafa Powell has run himself out of the title race with another poor performance Friday.
Speaking to BBC Five Live on Saturday, Campbell said Bolt is definitely the man to beat in the 100m, but feels Gay, who is confident he can defend his titles in Berlin, will be a bag of problems over the half-lap.
"I predict Bolt wins the 100m in the low 9.7s ahead of Gay," the former Olympic 200m medallist said. "The 200m will be closer [though].
"Gay may not actually run the 100m and if he only runs the 200m then I think he will beat Bolt."
Meanwhile, both Campbell and fellow BBC Sports analyst companion Steve Cram wrote off former 100m world record holder Asafa Powell chances of troubling the top two sprint kings over the 100m.
In fact, Campbell is yet to be convinced that Powell can even win a bronze medal come Berlin, after the Jamaican disappointing sixth place finish behind Bolt in the 100m in London on Friday.
"I’m sitting on the fence for bronze because I don’t think it will be one of the usual suspects," Campbell said.
Cram in the meantime, added that Powell’s performance on Friday did him no justice, as he failed to deliver the confident sub-9.80 seconds performance he promised the day before.
After getting out to a slow start in Friday’s final, Bolt quickly made up grounds on the field before shutting things down at the 60-metres mark to record an easy win in 9.91, running into a strong headwind.
Surprisingly Powell, after getting out well, fainted to sixth in 10.26, this after running 10.19 in the heats.
"Asafa Powell’s the one who keeps writing himself out of the equation," Cram explained. "He should be good, should be better and should be quicker, but every time he comes up against Bolt he just seems to wilt away."
"Bolt should win the Worlds though. The weather could play its part. It won’t be like Beijing and if it’s warm then we could be looking at a 9.7. A new record may just depend on Bolt and what he fancies."
Gay is the defending champion in the 100m and 200m, as well as a gold medallist in the 4x100m from the last championships in Osaka in 2007, while Bolt is the Olympic champion and world record holder over those events, after dominating the track in Beijing last year.
"I felt going into Beijing that Gay could win but he was unfortunate with his injury. All we want is Gay and Bolt getting it on in the 100m, 200m and relay [in Berlin]."