EVANSTON, Ill. -- Northwestern athletics director Derrick Gragg pushed back against a T-shirt several football staff members wore at Wednesday's practice that supported former coach Pat Fitzgerald, calling it "inappropriate, offensive and tone deaf."

The T-shirts read: "Cats Against The World," followed by "51," the number Fitzgerald wore as a two-time national defensive player of the year at Northwestern in the mid-1990s. Gragg, who attended Wednesday's practice, said in a statement that neither he nor the university had been aware the shirts would be worn Wednesday, the first preseason practice open to the media.

Sources told ESPN that the T-shirts were made shortly after Fitzgerald's July 10 firing and had been worn during other team activities. A current Northwestern player was seen wearing the T-shirt in a photo shared on social media July 27 by wide receivers coach Armon Binns.

"I am extremely disappointed that a few members of our football program staff decided to wear 'Cats Against the World' t-shirts," Gragg said in the statement. "Neither I nor the University was aware that they owned or would wear these shirts today. The shirts are inappropriate, offensive and tone deaf. Let me be crystal clear: hazing has no place at Northwestern, and we are committed to do whatever is necessary to address hazing-related issues, including thoroughly investigating any incidents or allegations of hazing or any other misconduct."

Wide receiver Bryce Kirtz said the T-shirts are a symbol of team unity amid a challenging time for the team. Current players and coaches have remained in contact with Fitzgerald, whose eldest son, Jack, is a freshman tight end on the team. Jack Fitzgerald has been working as a student assistant but remains on the roster. He attended Wednesday's practice but was not in uniform while assisting during position drills.

"[Interim coach David Braun], he's been preaching that we should stick together, especially during a time like this," Kirtz said. "The shirts are really a reminder, allowing us to stick together."

Braun, the team's defensive coordinator who became interim coach days after Fitzgerald was fired, said his sole focus is supporting the current players and staff members and ensuring the coming season is a positive experience for them. He said of the T-shirts, "It certainly isn't my business to censor anyone's free speech."

Speaking for the first time since Fitzgerald's firing, the players said they're focused on supporting one another and moving forward, despite 14 lawsuits from former players alleging hazing and other mistreatment within the program. No current or former players have been named in the lawsuits, and other than Fitzgerald, all coaches and support staff are set to work during the 2023 season. Defensive backs coach Matt MacPherson, who has been named in several lawsuits and is being investigated by the university, was on the field for Wednesday's practice.

Fitzgerald has denied any knowledge of hazing within the program. He hired noted attorney Dan Webb for a potential wrongful termination lawsuit against Northwestern, which fired him for cause.

"We're not addressing any past hazing allegations," linebacker Bryce Gallagher said. "What I can tell you is right now we have a great culture in our locker room and the guys are really sticking together through all this. The older guys are really just focused on helping these younger guys out, helping each other get through this, and just leaning on our relationships."

Gallagher said players were "devastated" upon learning Fitzgerald had been fired.

Players and Braun have been in touch with Pat Fitzgerald during the past few weeks.

"There has been a certain level of checking in on someone that, at the end of the day, provided an opportunity for me and my family," Braun said of Fitzgerald, who hired him from North Dakota State in January. "I care about his personal well-being very, very much."

Northwestern players went through a mandatory, in-person anti-hazing seminar last week before beginning practices. Braun said hazing has "no part" in the team's activities going forward. He was pleased to see only seven players, mostly incoming freshmen, enter the transfer portal in the 30-day window after Fitzgerald's firing.

"It just shows that what we have here is valued," defensive back Rod Heard II said. "The players that stayed, they want to be here. And the players that left, we fully support their decision in doing so."

Gallagher said practicing has been "a breath of fresh air" as the team prepares to open its season Sept. 3 at Rutgers.

"We've had a great training camp so far," he said. "It's been really nice getting up there on the field and just competing, helping each other out, helping [Braun] and the younger guys out and help develop them."