"I was pretty happy about it," Green told AllCyclones.com on Thursday. "Pretty cool being offered from them. I talked to my Coach and he was very excited about it as well."
On Wednesday, Nagel said, "It was a really experience for me to be offered by them."
The two have been teammates on the same Chicago-area 7-on-7 team since they were freshmen.
"We haven't talked too much about [playing together in college]," Green said. "We just congratulate each other on scholarships and everything."
Iowa State's offer brings Green's FBS total to six, including Illinois, Iowa, Purdue, Boston College and Toledo. The 6-foot-2 three-star is hoping to get to ISU's Junior Day on March 8.
"They will be a school I consider," Green said in reference to his ultimate decision. "I'm trying to go down there (for Junior Day) but I don't know. Hopefully I'll get down there."
While Nagel is a slot type, Green is better at high-pointing a ball.
"I'd compliment Flynn's speed, he makes some good moves in open space and is good with his hands," Green said. "I [can get] the jump balls and create space against a defensive back."