Lagers require quite a bit more yeast than an ale. The yeast will multiply to numbers sufficient to ferment the beer. But while this is happening they are stressed and will create off flavors.
You can make a starter or pitch more yeast. The main idea behind making starters is to pitch the proper amount of yeast without pitching multiple vials of yeast.
For your lager you would be looking at 3, 4 or even more vials of yeast. If you make a starter you use one vial and some dme. So you can do that for ~$10 rather than $21 & up for multiple vials.
I would make the starter and put off brew day until it is ready.
Or, make something else in the meantime.
Check out mrmalty.com and yeastcalc.com for information on starters.