"From my personal perspective, it's been a really disappointing three test matches so far," the 32-year-old all-rounder said.
"To be able to get the starts and get things going and then not to be able to capitalise on that has been extremely annoying.
"I certainly do love opening the batting in all forms of the game. But even in the second innings (of the Old Trafford test) I absolutely do understand the thought process behind it (the move down to number four)," he told ESPNCricinfo.com.
"I also haven't scored the runs as an opener ... to be able to continue to feel like I'm doing a competent job at the top of the order. In the end, I'm happy to bat anywhere."
Watson opened for Australia between 2009 and 2011 but, before this series, had moved up and down the order since returning from injury.
Warner, who missed the first two tests in the wake of his suspension for hitting England batsman Joe Root in a bar, scored 41 in Australia's second innings at Old Trafford when the touring side were looking for quick runs.
The fourth test of the five-match series starts in Chester-le-Street on Friday with England 2-0 up.
(Reporting by Robert Woodward; Editing by Mark Meadows)
