The former Southend and Yeovil marksman, who had been on trial at the Don Valley Stadium, was touted as a possible replacement for Reuben Reid following his switch to West Brom.
But Robins, speaking after Saturday's 2-0 win over a Manchester City XI, told the club's official website: "Wayne has now left the club. I made the decision the other day that I wasn't going to pursue the situation any further.
"With that in mind we need to free up the space so we can get games in for Ryan Taylor, Paul Warne and Tom Pope."
In fact, it was goals from Taylor and Pope that proved the difference against a youthful City XI and Robins was pleased with the showing ahead of next weekend's opener against Accrington.
"It was a great workout and exactly what I wanted," he added.
"Once things settled down we took control but, to start with, we did have trouble getting bodies into the box. We put some good quality into the area so if we can get the bodies in there and gamble then we will score a lot of goals."