The Pilgrims’ defensive game plan to just sit off Rovers worked as they left Keepmoat Stadium with a 1-0 win that closed the gap at the top of League Two to three points.
But Ferguson fully expects Marcus Bignot’s Mariners to come out all guns blazing in today’s 1pm kick off.
“I would expect it to be quite competitive and I would expect plenty of tackles,” said Ferguson.
“We’ll have to deal with that side of things.
“They won’t be like Plymouth. They’ll have a right go at us and press us, I think they’re quite aggressive in that sense.
“That might benefit us, we’ll have to wait and see.
“We’ve done a bit of work on that but if they don’t [press], then we know how to play against it because obviously we had a good example of that last week.
“We’ll be absolutely one hundred per cent ready for this game.”
Rovers could be promoted today if they win, Stevenage lose at home to Barnet, and Blackpool and Luton Town draw against each other.
Ferguson said: “The focus is on beating Grimsby and then after that we’ll hopefully be on the bus with the three points having done our bit.
“That’s all I’ll focus on this weekend. I’m very aware of not looking too far ahead.
“If we do our job and other teams slip up and we get it, fantastic.
“But we’ve really just got to concentrate on winning this game, after a defeat, and keeping the pressure on everyone around us.”
Gary McSheffrey and Luke McCullough are on standby to replace Conor Grant (groin).