It's a little difficult to tell from the photo, but this looks to me like it could be either crabgrass or goosegrass. 

https://www.canr.msu.edu/ipm/diseases/smooth-crabgrass?language_id=

https://www.canr.msu.edu/ipm/diseases/goosegrass?language_id=

If it's either of these, they are summer annuals, so the best thing to do would be to put down crabgrass preventer in late March-April. Also, these weeds have a leg up on your turf grass when fertility is not managed properly, soil is compacted, and inadequate moisture is supplied throughout the course of the season. Management practices such as increased mowing height, managing fertility, adding organic matter (leaving clippings and mulching leaves into turf) and/or aerating to decrease compaction, and irrigation may help to produce a dense vigorous turf capable of outcompeting these weedy species.

It could also be quackgrass. https://www.canr.msu.edu/ipm/diseases/quackgrass?language_id=#gallery

Or tall fescue https://www.canr.msu.edu/ipm/diseases/tall-fescue?language_id=#gallery

These grassy weed species are perennial and can be very difficult to manage outside of mechanical removal. It's unfortunate that there aren't as many options for managing those weedy perennial grass species. Typically they are only very noticeable early in the spring, so raising you mowing height is a good option for camouflaging and will help with overall turf health.

If you could send me a wider shot of the lawn, that would be helpful for further ID.