The former England and Leeds Rhinos captain won virtually every honour in the 13-a-side code, including being named World Player of the Year in 2012, before deciding to seek a new rugby challenge late last year with Yorkshire Carnegie after steering the Headingley side to the treble.
Runner-up in the 2015 BBC Sports Personality of the Year award, the 34-year-old is hoping to shake off a calf injury, which kept him out of Sunday's win over Cornish Pirates, to play in Saturday's Championship derby at Castle Park.
If he does play Cooke believes Sinfield, never the biggest or fastest of players, will pose a big threat despite his relative inexperience.
“It’s difficult to learn the game in the time-frame that he’s been given and he does make some errors mainly due to his limited knowledge of the game," said Cooke.
“But what Carnegie have got is a really smart player who kicks the ball accurately and who knows how to guide a team around the park.
“He showed some really nice touches when Carnegie won easily at Ealing recently and if he does play on Saturday, or we come up against him in the play-offs, we need to be aware of what he can do.”
Cooke admits that switching codes was a gamble for Sinfield given he has no previous experience of the game but feels he can make a success of it.
“Even if it doesn't go as well as he hopes, his rugby league reputation will still be untarnished,” he said.
Although Sinfield, who operates at fly-half in union, will be the centre of attention if he plays, Cooke is quick to point out that Carnegie are no one-man team.
“They are very good team and are well organised,” he said. “They do the right things at the right time and it’s going to be a very difficult game for us.”