The type of surgery required for Sizemore sidelines him for six to nine months to recover. In terms of just selling seats and competing in the AL Central, this will only hurt the Indians more and could force a trade.
AL sources have already informed me that the Indians are making plans to aggressively shop pitcher Kerry Wood, first baseman Russell Branyan, and outfielder Austin Kearns.
The major problem I see with the Indians make up is that they have very few long-term guys on their roster. They have one pitcher with an over-500 record, a pitcher only in his first professional season (Mitch Talbot). The offense is abysmal, with Shin-Soo Choo being their best bat with a .276 average. Prospect Matt LaPorta has been demoted to the bench, and second baseman Luis Valbuena has been hitting under the Mendoza-line for the past several weeks.
Chris Perez is likely the teams future at closer. But besides that, the Indians need to invest in some long-term options around the field. Down in their minor league system, Lonnie Chisenhall and Beau Mills are offensive prospects, but catcher Carlos Santana is ahead of both them in terms of development.
The team needs to find away to add some depth that is more than a one year option (ie. not Austin Kearns).