Games behind
Dejen competed indoors for the first time the following year and was second at the Boston Indoor Games behind Lagat. He was also the runner-up at the Birmingham Indoor Grand Prix two weeks later and was selected to represent Ethiopia over 3000 m at the 2010 IAAF World Indoor Championships. He ran the second fastest qualifying time (a personal best of 7:44.26 min), but did not perform as well in the event final, coming tenth. Outdoors, he was second at the Carlsbad 5000, the Prefontaine Classic, and the DN Galan (at which he ran a personal best of 12:53.56 min for the 5000 m).