He's been pretty good defensively as of late. Considering how much time that we've spent discussing how we need a defensive RHD, I am surprised that Zaitsev does not get more support around here. Frankly, at ES the Gardiner-Zaitsev pair has been excellent defensively. Zaitsev is playing very tough minutes (which he's not suited for, this is classic Babcock trial-by-fire defense coaching) and is handling the defensive responsibilities as well as he can. Gardiner has looked great defensively too, but that's a different thread. In my opinion, Zaitsev is a very solid defender who can succeed in second pairing minutes. Top pairing minutes are too hard for him, but he's at least treading water defensively.
However, this comes with major "BUT"s. The first is that his metrics are absolutely ass. My own theory on this is that while his defensive numbers are good (his corsi against is quite reasonable considering the minutes and competition that he plays) his offensive numbers are abysmal. So while he's good enough at preventing shots against, he is a negative at producing shots, which means negative corsi and xGF numbers. This is very much a result of the second issue, which is that the guy just cannot make a breakout pass to save his life. His defensive zone draw rates are probably increased because he ices the puck so damn much. I've been a fan of the Gardiner-Zaitsev pairing because Gardiner's strengths as a transition player help cover up Z's weaknesses, so even though Zaitsev's metrics are negative, the pair actually does quite well together. It's not ideal, but the sum is greater than the individual parts.
At this point I'm mostly hoping that Zaitsev continues to refine his defensive game and gets more comfortable with in-zone passes to cut down on the icings. His contract isn't great, but if he's a defensive stalwart then at least he's a useful piece that we can keep in our top4.