At the time, Okpako was acknowledged as one of the best holding midfielders in the domestic league, but was as shocked as league watchers when Siasia told him he was not good enough to make the squad to Egypt.
"I was surprised, but I was not disappointed because football has its ups and downs for every player and I felt that maybe it was not my time," Okpako told KickOffNigeria.com.
"But when the coach dropped me, he told me the things I was doing wrong. Some of the things he said was that I was not going forward enough and I was not joining up quick enough with the rest of the team when we were attacking.
"So I went back to Kano Pillars and I told them what the coach said and what he asked me to do."
Okpako, who will turn 20 in May, said the change was almost instant.
"The coaches there helped me to work on it and I started seeing the improvements.
"Before, I could only play as a defensive midfielder, but now, I can play as an attacking midfielder like I did in some games at the WAFU Cup, and I can also play as a support striker.
"Also, I never used to score goals, but I scored three goals at the WAFU Cup, and it is all because of what Siasia told me. I believe I am a better player because of him."
That was not the first time Okpako would suffer rejection. Starting his league career with Bendel United in 2005, Okpako left them when the club were relegated that year. But he was turned away by city rivals Insurance when he attempted to join them for the following season.
With nowhere else to go, the midfielder spent a full season at home before packing his bags and heading up north to join Kano Pillars at the end of the 2006 season.
"I just didn’t know what to door where to go after Insurance rejected me. But I always believed that God would make a way for me."
Over the weekend, Okpako was one of six players from the domestic league named by Lars Lagerback in his 44-man provisional World Cup squad, and he says it did not come to him as a surprise, after consistent performances with Pillars.
"From the way I have been playing, I believed that I would be invited," he said.
Now, it is time for him to go one step further and prove his worth on the biggest stage of all "All I can do is go there and give my best. If the coach likes what I do, maybe I can make it. But I don’t want to think about anything but how to work hard and give my best."
Solomon Okpako Fact File:
Date of Birth: May 1, 1990 State of Origin: Delta State Height: 5'7 Weight: 68 kg Position: Holding midfield Other positions: Central Midfield, Support Striker Previous clubs: Bendel United 2005, Current club: Kano Pillars