DWood: I'm not entirely clear on what the op wants the MC to do, so if any of this misses the mark, it's because I'm misunderstanding what you're after.
To my mind, if you want the MC arriving late to the box, this might have more to do with mentality than anything else. If he's got a high (attacking) mentality, I assume this means he'll be at the forefront of attacks your team puts together. So far from arriving late -- he'll be one of the first on the scene. Players on a lower mentality will only join in if there is less harm in doing so, so maybe that helps them arrive late.
To me then, an attacking MC may be a bit ill-suited for *arriving late*, whereas using someone like a DMC for this might be more appropriate.
If what you meant was that the MC rushed forward to ignite an attack, but then hung back in the box, or if you're just trying to get the MC to get more action in the box, then it may help to give him a free role and low closing down, or whatever equates to high creativity/gets in space within your offense. If the player is capable of thriving in this kind of situation (i.e., Riquelme) you can see a lot of cool goals.
In my game he used to hang near the back of the box a lot, and when a defender made a bad (short) clearance, a decent number of times he'd be right there to smash it right back on net. (It may have helped his positioning that he is kind of slow, IIRC, which meant that my attack (slightly quick, direct, attacking) often started to develop before he was on the scene.) I don't think he was on the receiving end of too many crosses though, although his general inability to do much with them probably helped. In my experience, wingers rarely look to at an MC as a target for crosses, although a target man designation would obv fix that. As for Riquelme, I had him set on free role (high creativity, too, if that made a difference), low closing down, and long range shots often. Probably on forward runs often, although usually no farrow, and he played MC, not AMC.
Hope that helps with the ideas.