The great USA swimmer surprisingly finished fourth in the 400m Individual Medley final on Saturday night and had to settle for silver when France won the 4 x 100m Freestyle Relay on Sunday evening.
But the 27-year-old from Baltimore is expected to take centre stage when he bids to become the first male swimmer to win the same individual event at three successive Olympic Games in the 200m Butterfly.
Phelps has dominated that event, winning every Olympic Games and World Championships he has competed in since 2001.
He will also have another opportunity to add to his huge gold medal collection when he lines up in the 4 x 200m alongside Ryan Lochte.
Chinese teenage sensation Ye Shiwen has made a huge impact in the pool already and the 16-year-old will be favourite to win the 200m Individual Medley.
Ye produced a stunning swim to break the world record and take gold in the 400m Individual Medley on Sunday, producing a mind-boggling final 50m freestyle that was quicker than Lochte in the men’s final.
The women’s 200m Freestyle final will also be eagerly awaited, with world record holder Federica Pellegrini, young USA swimmer Missy Franklin and Sunday night's 400m Freestyle gold medallist Camille Muffat vying for medals.
In Gymnastics, USA, Russia, China and Romania will be the leading contenders to take the medals in the women’s Team final at the North Greenwich Arena.
Great Britain qualified in fifth to become the first British women’s team to reach a final since 1984 and they will be looking to the experienced Beth Tweddle to inspire them.
The Germans are on a score of 124.70, 5.5 penalties ahead of Britain, with Sweden third. The Individual competition, meanwhile, has joint leaders in Germany's Ingrid Klimke and Swedish rider Sara Algotsson Ostholt.
Mark Todd, the 56-year-old New Zealander chasing a third Olympic Games title 24 years after his last one, is third, just ahead of world champion Michael Jung. The top four medal contenders are separated by only 1.3 penalties so a thrilling climax is in store in Greenwich Park's main arena.
Chen Ruolin and Wang Hao are strong favourites to continue China’s dominance of the Diving events when they compete in the women's Synchronised 10m Platform final.
Australian duo Loudy Wiggins and Rachel Bugg will be eyeing a medal, as will Meaghan Benfeito and Roseline Filion of Canada. Home hopes rest with Tonia Couch and Sarah Barrow.