Leeds are on their way to the Challenge Cup Final in Cardiff in a fortnight's time, and Sinfield's return also comes as the Great Britain captain and loose forward Paul Sculthorpe has been ruled out of the autumn's Tri-Nations tournament.
Sculthorpe had an operation on Wednesday to repair the lining of his knee joint and he will be on crutches for six weeks.
"It's very disappointing, but someone else will come through," said Sculthorpe, who said Sinfield and his Leeds team-mate Gareth Ellis were major candidates for his position. Sinfield was not picked for the Tri-Nations last year.
Terry Newton is expected to play for Wigan at Widnes tomorrow despite doubts about his fitness. The hooker needs a hip operation at the end of the season.
"Hopefully he will be able to play in the last five games, because he's such a key man in our squad," said his coach, Ian Millward.
"But he will need to have the operation sooner rather than later and that makes him a doubt for the Tri-Nations.''
Leeds' Challenge Cup final opponents, Hull, have Nathan Blacklock back in after a knee injury for their game at home to relegated Leigh. Paul Cooke, who has an eye injury, is likely to rest.