First of all, Seles injured her ankle at the Australian Open, and even though she was a good sport about it, something like that is going to affect how you play. Having not played much probably had something to do with her struggles in Tokyo, but keep in mind that was a high-level tournament, and reaching the finals is nothing to hang your head about.
Secondly, Lina Krasnoroutskaia is a quality opponent. I think she was in the top thirty (not 100% sure, though) when she got hurt last year, and in the past few weeks, she's started to play the kind of tennis that she was playing before she got hurt. Without that injury (I think it was an ankle injury), she could have potentially been a top twenty player or better at this point. She's still only 18 or 19 years old, so it's entirely possible that she'll get back to that level.
And it's not like that match was a blowout. The final score was 7-5, 7-5, so obviously she's not embarrassing herself out there.
Yes, Monica has had a bit of a slow start to this season, but I think that once she gets a few more matches under her belt, she'll be fine. If she's still struggling like this in a couple months, then maybe we can start to worry, but I don't think she will be.