All reports I've read are that he is fully healed and is already throwing mid-90s, topping out at 96 MPH. He had a lights-out rookie year with the Angels in 2008 as almost everyone on here knows, then got hurt midway through the '09 season and was out for the last 1.5 years. The Reds signed him to a two-year deal last offseason knowing he wouldn't be ready until 2011. Basically they paid him for rehabbing for a year with the hopes they would cash in this season.
I can't overstate how huge it would be for the Reds' bullpen to have Arredondo pitch even close to as well as he did three seasons ago. And in my estimation, if he's healthy, there is no reason to think he won't pitch well. If he was that good as a rookie, he should be even better three years later and with a healthy arm. I know it's not that simple, but I'm very excited about the potential of this young man. The Reds already have the makings of a solid bullpen with the five locks (IMO) to make the team in Cordero, Chapman, Masset, Bray and Ondrusek. But Arredondo is the type of player that could push the bullpen over the top, turning it from a good one to a great one.