Why does Liverpool want to buy another striker?

Well when one player leaves, the obvious logic is to replace him. With Baros' arrival, you'd think 4 strikers was enough.
 
Apparently theres some problem with Baros' work permit (summat to do with the 75% of international games rule, I think) and he may not join until next season. Which leaves us with only three strikers, barring injuries. As we play two strikers in our team (remember those days, mancs? ;) ) it leaves us a bit short at the moment. Unlike Owen who's always been short.