To be fair he rarely does either, or at least not effectively. If you were talking about his strengths, I wouldn't put tackling in his repertoire.Strolled about yesterday, wasn't bothered about blocking crosses or putting tackles in. Not sure how you didn't notice that.
Still I agree, yesterday he was noticeably poor in both areas along with other aspects of his play.
Some people are mentioning laziness, but personally I think it is unfair criticism. He's just lacking confidence and that's effecting his overall play.