Easterby's European form for the Scarlets has been undeniable though - he outplayed Neil Best, his closest rival for the Ireland number 6 shirt, when the Welsh region beat Ulster 35-11 at Ravenhill last month. The ability of the former Irish Exile to steal or slow down opposition ball makes his a constant threat around the field and Wales will certainly be wary of his presence at the breakdown.
"Simon's recent form has been excellent. The amount of work he gets through is sometimes twice that of the other back rows, which is incredible," O'Donovan commented.
"He's a great guy to read lineouts, particularly in defence, which means we can get guys in the air faster. He's a very secure guy on our own lineout ball and if you have eight guys working as hard as Simon in the pack, you won't be beaten."
With the provinces' set pieces coming in for criticism in the final matches of the Heineken Cup's pool stages, O'Donovan has taken heart from the amount of work the players got through in training this week, adding that Ireland's game plan is probably "geared more around solid set pieces" than Wales' is.
"I've been thrilled with the way we've worked this week. Obviously we have looked at some of the faults that happened over the last two weeks (with the provinces) and in the November internationals," he said.
"But these were slight, individual things. It only takes one guy to be out of sync in the lineout to cause problems.
"People are talking a lot about the Munster-Leicester game when the perception was that Munster were beaten in the lineout. But Munster actually got four throws off Leicester while only conceding two of their own."