The left-back has also made over 500 appearances for Hearts, Livingston, Aberdeen and Queen of the South, and having signed such an experienced player, Johnson said McAllister is in the running to be the Glovers skipper.
"He's captain material and even if he wasn't wearing the armband, he'd walk around and play like a captain," he added.
"If he gets it, good luck to him, we'll see how pre-season goes, but he certainly will be one that ticks all the boxes for that.
"There is a few bits a pieces that have still got to happen [with other transfers] and that'll be one or two lads in the next couple of days.
"We've worked very hard over the summer and we've managed to get a good strong squad of 16 lads who will all be announced at the time."
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