His bowling during the Ashes was rather limited as Australia's pace attack and spinner Nathan Lyon took care of England in a 4-0 thrashing.
With a four-match Test series in South Africa starting on March 1, Marsh took four wickets against New South Wales in what was the last chance for Australia's Test squad members to impress before going on tour.
In quotes published on Cricket Australia's website, Marsh said: "It's good for my confidence that's for sure.
"I've been building for most of the season with my bowling and playing Test cricket with the big four that we've got, I don't necessarily have to bowl a lot of overs.
"But it's nice to know that I am capable of getting through 26 overs. I thought my pace has been up the last couple of weeks which has been really good and I'm happy with the way it's coming out."