
Reports in the Burton Mail suggest the 20-year-old, who joined the Evo-Stik Northern Premier - First Division side in January, improved his distribution rapidly as the season continued.
As well as maintaining an excellent starting position for crosses, shots and passes, Roberts made several first-class saves, the most notable of which came in his sides' 3-1 win at Lincoln United.
Roberts made four point-blank stops and tipped several stinging efforts round the post as United set siege to the Gresley goal in the opening stages.
But a fractured collarbone suffered in the final league game of the season against Stafford Rangers prematurely ended his season.
Thornhill is hopeful that a deal can be reached with Walsall and says the Moatmen have asked the question over whether Roberts could return on loan in 2015/16.