"Close" does not need to be "right next to the player".
I disagree with what you seem to be saying attempt means. Attempt means an attempt to touch the ball, not an attempt to get in position to then be able to make an attempt later. It is designed to address the plays where the on-ball play effort doesn't touch the ball, but freezes a defender. In this case, it was very clear that Maguire was attempting to play the ball and that led to the challenge.
I don't think this is possible for the reason above. If a defender reacting fouls him before the ball gets there, then there wasn't an attempt yet. If anything, I think with an opponent there, you'd have to get to challenging an opponent for the ball from what you're describing, not attempt. It's offside in law. If you don't call offside on this type of play when it's clear the defender is impacted, then you might as well not call offside until Maguire touches the ball.
Well, that is the general trend of OS for the last many years. Anything other than playing (touching) the ball is very narrow.
Calling offside on this play is a judgment call, NOT one of black and white. Which leads to
@socal lurker 's post below.
The second bullet point is why I am very comfortable making a decision of offside that is correct in law (and not, as insinuated, some attempt to appease players for the sake of match control). Maguire is heading to where the ball is going. He can judge where the ball is going to land, and he's going to that spot. He's playing the ball and seeking to gain an advantage.
Can't be. "Playing the ball" requires touching it and "seeking to gain an advantage" left the LOTG a long time ago with "gaining an advantage" limited to the very narrow scenario of touching a ball that has rebounded or deflected. Neither can justify an OS call here. Both items meet the criteria to call offside as in the photo.
We cannot be sucked into some binary, black and white determination of when the ball is close enough. Different factors will be in consideration that referees must determine. If the attackers play a through ball and two players (one onside, one offside) are running near the ball, I'm going to see which one plays the ball to see whether the offside player plays the ball. In a case like this play, I'm comfortable making a judgment that
a player running toward a crossed ball is playing the ball and gaining an advantage by making the defender place himself in a position where he may foul the attacker.
I don't want to be aggressive, but this is really just wrong under the modern interpretations. I think that case could have been made a decade or so ago, but it's pretty clear that merely running towards the ball is not enough (and as noted above it cannot possibly be considered playing the ball or gaining an advantage as those terms are defined in the LOTG. I think the only ways you can get to an OS call is either finding him challenging an opponent for the ball (and it doesn't sound like that, but as I've said I haven't seen it), or more likely concluding that he got in the way of the defender, which would be enough under the second bullet I posted above.