#2 Sebastian Buemi
Sebastian Buemi was part of the Torro Rosso unit and Red Bull driver academy before he was deemed not good enough to drive for the Red Bull team. Ever since Buemi has competed admirably in the Formula-E series.
First with the Renault and currently Nissan team while at the same time enjoyed great success in WEC as he won the LeMans last year. As Alonso's teammate, he goes into the race as an out and out favorite to win
#3 Kamui Kobayashi
A driver that brought the Japanese Daredevil nature to overtaking in F1, Kamui Kobayashi was a great addition to the Formula One grid while he was a part of it. He drove great races in the midfield and used to pull off some great overtakes.
He would be driving the dominant Toyota alongside Mike Conway and Jose Maria Lopez. If something does happen to the trio of Alonso, Buemi, and Nakajima his team will be there to pick up the pieces.