Watford striker Isaac Success is expected to leave Vicarage Road in January.
A new club is already being sought for the Nigerian international to give him more minutes. He came close to a loan move to Hull City in August, but the deal fell through at the 11th hour.
Ward believes the Clarets defence will be forewarned about Gray's abilities.
"We'll just get one of our lads to kick him early on," he joked.
"We know all about him and it'll be good to see him. We all know what he did for us. He's got pace, power, he can score goals, it's as simple as that."