Michael Phelps of the United States competes in the final heat for the Men's 200 Meter Butterfly during Day Four of the 2016 US Olympic Team Swimming Trials at CenturyLink Center on June 29, 2016 in Omaha, Nebraska. [Photo/VCG]

While Phelps, who will celebrate his 31st birthday on Thursday, has turned his life around away from the pool, in the water he remains as demanding and critical as ever.

Aside from the result, very little in his 200m swim on Wednesday evening pleased Phelps, the winning time of 1:54.84 well off his world record mark of 1:51.51.

"I haven't felt great in the water but like I said, I'm checking a box off, being able to get on the team," said Phelps.

"Getting on the team was the most important thing and that was the only thing I had to do tonight," he added.