The 5-foot-11, 190-pound cornerback currently has scholarship offers from UAB, Iowa State and Washington State.
Antonio told Cyclone Sports Report that Iowa State has really picked up its recruitment of him during the spring season.
"Coach Wells came to a couple of practices this spring and he told me that the staff also watched my highlight tape," said Marshall. "He said they like that I'm real physical and that I can cover. Physicality is definitely the strong part of my game."
Antonio has also had a solid conversation with Cyclones head coach Paul Rhoads.
"He told me that he really wants me at Iowa State," said Marshall. "He wants me to come to Iowa State for a visit to see me in person and so that I can check out all the facilities."
If all goes well with his classes, Marshall will graduate next winter and get to take part in spring practices with the school that he eventually chooses to attend.
"That's the main reason why I decided to stay in Iowa for the summer was knock these classes out," he said. "If I can graduate in December I will have a big advantage of having spring practice rather than not coming until next summer."
While Marshall might graduate early he won't be making any final decision in the near future.
"I definitely won't be making a decision this summer," he said. "I first want to take some visits and then I'll probably make my decision before my season is over in the fall."