First of all, Valdez has been solid so far. Yes, small sample size and all that. But no closer converts 100% of save opportunities.
I don't think Tanner Scott is ready to take over the closer spot, there's also not another really valid option at the moment.
Valdez wasn't sharp tonite and it remains to be seen if he can close at a consistent clip. I don't see the harm in letting him keep getting save opportunities until he shows he's not the guy for the job. This year, anyway.