Ireland go into the match with Spain in Valencia as heavy favourites.
The Spanish were rolled 40-6 by Russia last week.
McDonnell, who has an Irish mother, makes his return for the Wolfhounds after last playing for them in 2014.
“The prep is going well for Ireland, we’ve had a few training sessions now and leave for Spain today and will finish off our training there before playing on the weekend,” he told Love Rugby League.
“We’re confident that our build up is coming along and we will see where we are at after our first game and our goal is to qualify for the upcoming World Cup.”
McDonnell has left St Helens and said he has made no decisions at this stage whether he will play on in 2017.
“There’s no decision that has been made on my future ye,t I will still wait to get home and see how I feel,” he said.
“If and when I do move on from full-time rugby league I’m looking to start a career in real estate, however along with some other projects in property development.”