Dubuisson continued his impressive run of form by finishing runner-up to Jason Day at the WGC World Match Play Championship and his spot in the Ryder Cup is now almost secure following the display in Arizona.
"It looks like with the points he has accumulated he is a nail-on now," McGinley told Sky Sports News after Sunday's final between Day and Dubuisson. "If he was 90 per cent before the week he is 99.9 per cent now.
"With all the evidence we have seen this week I think he will be a very welcome addition to the team.
"You can't help but be very impressed. A lot of us were all learning about Victor and the fortitude he has shown under pressure all week has been most impressive."
Dubuisson would be making his first Ryder Cup appearance at Gleneagles.