There is so much wrong with the Titans right now that it is impossible to put a number on the things that need to be fixed, but I do think there are three areas where they can make some personnel changes that will might serve as a band-aid for the rest of the season.
Is Velasco much of an upgrade from Harris? Who knows, but it can't hurt. I have also heard that Velasco brings some of that nasty attitude that this line just doesn't have.
There are more problems on defense than Ruud right now, but he has been terrible. Again, McCarthy can't be worse. They should get him out there so they can know if he is guy they can build around or not.
3. (Stole this idea from hal) Pick your 5 favorite offensive skill players and find ways to get them on the field at the same time.
Careful, this is going to require getting creative, but what other choice does Chris Palmer have at this point? This group of wide receivers is terrible. Terrible. Lavelle Hawkins is not an NFL receiver. Damian Williams doesn't look like one either.
Forget about what positions you think these guys are and just get the most talented players on the field. If that means splitting Chris Johnson out wide and putting Javon Ringer in the backfield- do it. If that means finally admitting that Jared Cook isn't a tight end- do it.
This offense, as it is currently constructed, is terrible. They are going to have to think outside the box to score points for the rest of the season.