He told Setanta Sports 1: "Aberdeen are always a tough team to play against and, when you come to Pittodrie, you know you're going to get a hard game.
"You know the first 20 minutes, half an hour, they're really going to come at you and it's how you deal with that.
"I thought we dealt with it okay and we gave away a stupid free-kick and, as we saw the last time we were up here, that was our Achilles heel.
"But, thankfully enough, maybe a bit of fortune getting back into it before half-time and I thought we played excellently in the second half."
Celtic conceded four goals from crosses on their last visit to Pittodrie and McDonald added: "I think it was well-documented the last time we were up here and I think that's where we had most problems.
"Charlie Mulgrew's got a great delivery and has proven that once again.
"You're going to get goals against you in the season.
"Everyone highlights the Old Firm goals because they're the most important teams in the league.
"We believe in the way we defend and it's good balls that beat us."