Running velocyto on adata object

[AnuSitu1]

Hi,
I was wondering if it is possible to run velocyto on my already processed adata object.
I was trying to run cellrank and realized that my object does not have the spliced and unspliced layers already.

The object I have is subsetted from a global data set. I do have access to the fastq and bam files but only for the global dataset. I fear that I may have to run velocyto for the entire object, preprocess and subset again before finally running cellrank. This would mean starting my analysis from scratch. Is there anyway to circumvent this?