He told the Daily Star: "I have never doubted my ability and although the football didn't go too well last season, I was Everton's top scorer 12 months ago and was getting touted to go to the World Cup.
"I was disappointed but life goes on and I am very excited and looking forward to a fresh challenge."
Eyebrows were raised at Beattie's decision to take a step down to the second tier as he completed his club-record £4million move to Bramall Lane, but the 29-year-old sees his stay in the Championship as more of a short-term measure.
"It is a step down in leagues, but Sheffield United is a massive club with great support and hopefully I can help us get back up there," he continued.
"I have 81 Premiership goals, so hopefully I can add a few Championship goals."