He stayed at home to watch the champions league matches.Looked out the window saw it was raining in November at home against Boston,who could blame him.
How about another possible, and far less reactionary reason...
McGhee knows all about Jake - big potential, star of the future etc etc. He's staying with the Albion no matter what, but is not up to regular first team football yet.
Leon Knight is scoring goals for fun and has his place in the side.
His other options up front look less solid - McPhee and Marney. Still young-ish but yet to set the world alight. So McGhee uses tonight's game to give them a runout in a competitive fixture. If he wants to bring anyone in, he has to lose some money off the wage bill so he has to take a look at players in action to determine who he can loan out/sell (release for free) in order to raise money to allow him to get people in.
The above is possible, as are a million and one other reasons for tonight's squad. Most of the rest of us are not infatuated with young Jake and, although curious as to why he did not feature tonight - are going be a little bit more relaxed about the whole thing.