Last season's pace setters Ulster failed to begin with a bang this tiem around after defeats to the Dragons and to Glasgow but have since bounced back by beating Connacht and Treviso.
And with both sides getting ready for the kick off to their Heineken Cup campaigns in a week-and-a-half's time, Tandy knows the Ospreys will have to be at their very best on Friday night.
"Ulster will provide us with a really tough test. That will be the perfect game to get us ready for Leinster in the Heineken Cup," said Tandy.
"Ulster are formidable opponents. They beat us at home last year and we snuck a victory out in Ravenhill.
"They're a well-coached team and they've got a lot of quality players. I watched them against Treviso and their defence was spot on. Treviso threw the kitchen sink at them towards the end and they didn't concede. So we'll have to be on the money.
"And then they've got a lot of attacking weapons, the likes of Jared Payne, Tommy Bowe, Craig Gilroy, Paul Marshall, Nick Williams, spot on people. They've got a real array of talent."
The same could be said of the Ospreys, though, with their Lions tourists among those setting the platform up front, Dan Biggar steering the ship from fly-half and plenty of pace out wide.
A comprehensive 44-10 bonus-point win over Edinburgh in Swansea in Round 3 was pretty special and so was a similarly impressive 43-20 success at Connacht last time out.
"The focus last year and this year is on what we do and how we represent ourselves," added Tandy.
"Yes, we'll obviously do our homework in and around Ulster but it's more about how we're going to affect the game on Friday night.
"Our last performance at home against was pretty decent but the standard of opposition is going to be much higher this weekend and we need to be spot on to keep our momentum going."
Skipper Alun Wyn Jones agrees with those sentiments but he knows that Ulster will be going all out to upset the apple cart.
"When you have a pretty poor start, you want to do everything you can to put that right. They'll see it as a great opportunity to come to us and take a scalp after we've started pretty well," said Jones.
"Hopefully we can just continue in what should be great preparation for the Heineken Cup."