Poonacha arrived from India on Saturday to take over as the Oman coach for the third time. Oman's next major international assignment will be the second round of Hockey World League (HWL) in Dhaka, Bangladesh that will be held from March 4-12.
The OHA will also announce the support staff of Poonacha on Sunday with Ahli- Sidab's assistant coach, Khalid Khalfan, favoured to take up that role.
Shakir Munir will continue as the national goalkeeper coach. Poonacha, who has been hired for a year, replaces Oliver Kurtz.
The German was fired as head coach in December 2015. Omani coach Ahmed al Darmaki has been serving as an interim coach since then.
The Indian World Cupper first served as Oman coach from February 2010-November 2011. After his exit, Poonacha, who has 52 international caps for India, took charge of Ahli-Sidab in April 2012.
He returned as Oman's coach, this time on an interim basis, towards the end of 2012, when the national team took part in the HWL in Doha, Qatar and the Asian Champions Trophy. However, that spell lasted less than a month.