The duo recently announced their entry into the contest which is already shaping up as a high-staked match between them.
Political analysts say the August General elections has presented the political combatants with a rematch that will test the two political rivals’ might.
In 2013, Lawyer Sang who at the time worked as a consultant on governance, democracy, and devolution, trounced Kosgey, then ODM Chairman, to win the Nandi Senate seat.
Sang who was vying on a United Republican Party(URP) garnered 171,988 votes against Kosgey's 32,368 votes in a political contest that had been compared to the biblical David versus Goliath fight.
However, this time round the political arch-rivals will be on a near-equal footing, as they both seek to be the Jubilee party flag-bearer in the race for Nandi governor with both having claimed that their entry to the race was occasioned by pressure from residents.
Kosgey, who recently announced that he will vie on a Jubilee ticket, is one of the most senior politicians in Nandi having served as MP for Tinderet for six terms and still commands a substantial following in the region.
Sang, on the other hand, has carved himself an unrivaled niche with his oratorical prowess and active role in legislation. He is also a close ally of the Deputy President William Ruto.
Meanwhile, they will have to content competition from other aspirants seeking to unseat incumbent governor Cleophas Lagat who include; Former Agriculture CS Felix Koskei, Silas Kipruto, Alphonse Misoi, Daniel Koech, Tirop Koech, Barnabas Sang, Anderson Serem and Peter Maiyo.