During the Boston Bruins most recent practice at Warrior Ice before heading to Colorado for their first road trip of the season, Tyler Johnson was present at practice.
Johnson has been apart of some of the Bruins practices', but is not eligible to play any games until he signs a deal. The fact that the Boston Bruins still have Tyler Johnson hanging around on a PTO makes it seem like they want to sign him to an NHL deal, but they just might not have the cap space to do it right now.
According to PuckPedia the Boston Bruins only have $426,090 in cap space, and would either have to make a trade or a roster move to create room to sign Tyler Johnson.
Right now it looks like the exact same situation Danton Heinen was in with the Boston Bruins last year when he signed a PTO in the off-season, and didn't sign an official contract with the Bruins until a couple weeks into the regular season, and Heinen would play a big part of the Bruins success last year.