After graduation in 2005, he joined military team Ulinzi RFC playing in the Kenya Cup league.

[8] In February 2013, Injera was dropped from the Kenya national sevens team and his contract was cancelled by the head coach Mike Friday.

This conflict led to Injera missing training sessions with the Kenya national sevens team and therefore breaching his contract.

[11] In 2022, He was recalled into the Kenyan squad for the Rugby World Cup Sevens in Cape Town.

[21] In 2010, Injera was awarded the presidential Order of Golden Warriors (OGW) alongside his brother Humphrey Kayange for their performance in the 2008–09 IRB Sevens World Series.

[24][25][26][27] He is also the second African player to be feted with the honor of being an official ambassador for the 2023 McDonalds Coral Coast Sevens, after Bryan Habana of South Africa in 2019.