The Warriors sealed their place in the final at Old Trafford by triumphing over Huddersfield on Thursday evening.
Now Lenagan would like to add a touch of Lancashire v Yorkshire spice to the occasion.
“I would like it to be Leeds, but I have a sneaking feeling that St Helens will beat them,” he said, according to BBC Sport.
“That’s then the ultimate between the two top teams and we haven’t played Leeds in a Grand Final since 1998 when Jason Robinson scored that try.
“I don’t want any parallels made with last year with Ben Flower and all that sort of stuff so in that respect I’d prefer it to be Leeds, but I still have a sneaking feeling St Helens might get there.”