Johnson returned to the United squad on Saturday after his dual registration spell with Hednesford Town came to an end.
“Andre went to get some games at Hednesford and it’s not worked out how he wanted,” manager Craig Elliott said, telling the attacker he will remain in his plans.
“There was never a falling out or anything, so he’s more than happy to come back.
“I’m happy to work with him in training and he gets on well with the lads.
Johnson will, however, have to force his way ahead of Jay Rollins, Gavin Allott and Jordan Slew in the pecking order if he is to add to his three Boston goals.
Elliott added: “Jay and Gav have done pretty well without scoring the goals they deserve with their performances. But there’s a point where that has to improve.
“If they don’t there’s Jordan Slew and Andre, and I’m working hard to bring another striker in.”
Margetts has returned to Boston following a three-month loan spell at Gainsborough Trinity.
Speaking on Saturday, Elliott said the striker’s future is yet to be resolved: “I’m not sure to be honest, I’ve genuinely not spoken to the lad.”