Ryan Leonard says he is determined and confident about making the step up from League One to the Championship.
Speaking having put pen-to-paper on a three-and-a-half-year deal at Bramall Lane, with the Blades paying an undisclosed fee for his services, the 25-year-old is positive about what the future holds for him at S2.
He remarked: "I owe Southend an awful lot, they've been absolutely brilliant for me for the last six-and-a-half years, but this is now my chance to make a step up in terms of the size of club and the league I'm playing in.
"I believe I'm ready for this new challenge and I'm confident I will be able to show that when I get a chance on the pitch."
On what he will bring to the group, Leonard added: "I'm very much an all action midfielder I'd say. I've generally played in a more defensive role at Southend, but I'm athletic and like to get on the ball.
"I don't score many bad goals either so a few more won't go a miss. Ultimately, I will always work hard for the team and give 100%
"Flecky and Couttsy have done brilliantly in the last year or so and we have Jonny (Lundstram) too, there just three midfielders here, but I want to come in and add something different to the group."