Just my two cents here. Is Zak struggling? Definitely. Would he be the first to admit that? Absolutely.
But there's no way you can bench him or limit his playing time. It doesn't make any sense. This team isn't going anywhere without a solid Irvin. You have to ride him and hope he breaks out of it. If he doesn't, so be it and they don't make the tourney. Their only hope of making it and trying to make a run is with him playing solid.
In baseball terms, you're not benching your 3 or 4 hitter even if they're hitting low .200's 2/3 of the way through the season. You absolutely need him to have any chance of going anywhere. Immediate relief isn't the best for the long term goals.