"Peter Stringer is a good player," said Cooper.
"His service is sharp and he gets the back line moving really well. He is like a little general and it's going to be difficult to get hands on him because he is so sharp."
Cooper is expecting a more stern challenge all round following the 23-10 victory over Scotland last Saturday, even though Ireland lost to France in Paris the same day.
"We were pleased with our performance against Scotland but we know this weekend is going to be a more difficult challenge. You have to look at this week rather than looking back," Cooper added.
"It's going to be very physical. Lansdowne Road isn't an easy place to go.
"I haven't played there before but everyone has been telling me that.
"The Irish pack are strong and very physical. They have a very settled team with experience throughout the spine of the team. Their pack gets through a phenomenal amount of work and they have real hunger to get in the game."
By contrast Wales, even though they will have Brian O'Driscoll to deal with at outside centre, have a back line which can score tries, as they proved against Scotland.
Cooper is only too aware of the responsibility of his role in unleashing the pace of Shane and Rhys Williams on the Wales wings.
"It is an exciting back line and last weekend we gave the ball to the back three and they make things happen. It is quite refreshing to know if we do that job inside, that things have the potential to happen outside.
"Most of us have been together now since the start of the last Six Nations Championship.
It has been like a family I suppose, like a club team because we have played so many games.
"We have been to Australia twice, we've been to New Zealand and this is our second Six Nations together."
Cooper has been Wales' number one scrum-half since before the World Cup but he knows he has to be on his toes with Dwayne Peel waiting in the wings.
"Since we have come back from the World Cup Dwayne has played exceptionally well," said Cooper. "Llanelli Scarlets have been doing well in the Heineken Cup and he has been part of that."
Cooper is part of an unchanged back line, though four changes have been made in the pack. The most curious is the axing of Duncan Jones for Iestyn Thomas at loosehead prop.
The other three changes are injury-related. Robin McBryde and Robert Sidoli return after missing Scotland with back and groin injuries respectively.
Out of the side is captain Colin Charvis, who is missing because of a dislocated finger he suffered in the second half last week. Martyn Williams leads the side in his absence.