The 19 year-old is regarded highly inside the club and also by manager Chris Wilder.
"I had two or three Championship clubs come in for him to take him on loan but we want him around us," Wilder said of Arblaster. "We want him to be involved in the changing room. I've talked to him about the culture and getting to know it. There have been a couple we've sent out because we thought it was the right thing and there are a couple we feel will be better involved with us and getting to know what we expect and demand off them.
"Ollie is one of them for sure. He's an outstanding young player. We did have a little bit of a setback with his injury at Port Vale, but he's worked hard to get himself back. There's no downside to having players not only with that attitude but that ability coming through, and we are delighted that we have. With our academy, we need to make sure the pathway is there, and we are strong in that area. We must keep producing young players and give them the opportunity to play."