Share other's misgivings. We were pretty lucky with injuries last season, and our league position was entirely down to how our defence performed. If we aren't as lucky with injuries again I'd be a bit concerned.
Obviously there is a finite amount of budget, and if these guys have been extended to allow for 2 or 3 real quality signings that we have prioritised then fair enough, it's a calculated gamble.
Still, would have preferred to see a couple of youngsters who may develop and happy to work alongside our first choice defenders, in the knowledge they would benefit and be ready to step in if required. The players at Blackburn and Swansea that have been mentioned previously spring to mind. I'd hope as a PL team we would be an attractive enough proposition for that type of player.