Bournemouth took the lead through Lewis Grabban's seventh goal in as many games 13 minutes before half-time and Harry Arter doubled their advantage when he drilled a fierce 73rd-minute left-footed shot into Yeovil goalkeeper Marek Stech's top corner.
Brett Pitman wrapped things up from the penalty spot for Eddie Howe's high-flyers after Yeovil defender Luke Ayling had handled.
Johnson said: "The first half was pretty even-steven and we had a couple of opportunities.
"But as the game wore on Bournemouth looked Championship quality. They got more effective and us less so.
"There will be some personnel changes here when the transfer window opens and some of the guys aren't up to it and are going to be shipped out. No names, but they know who they are.
"I'm playing people who I don't really want to.
"I've got a hit-list of players I'd like to bring in, but in the meantime, we've got to work very hard in the next couple of days to get things back on keel for our next game against Portsmouth."