Abreu has said before that he will not DH. To his credit, he improved his 1st base defense big time. However, it may simply become a detriment to the team at some point. Vaughn is probably a better defensive 1st baseman at this point. He definitely has more range. I'd imagine Sheets is better to. At some point, they'll just have to tell Abreu to suck it up and be the DH.