At the start of the season I'm pretty certain they could schedule a tandem start.
Either Manning or Peralta scheduled to go 5 innings, with the plan that Alexander comes in and finishes the game... 4 innings or otherwise.
It would keep him stretched out at the beginning of the season, give the BP a "rest" day, and within the first month, that would allow the team to figure out any adjustments needed. Which may or may not include pushing Ty into the BP as a long reliever, or slotting him in the 5th spot (if Manning or Peralta falter...), etc...
Isn't there a boatload of double-headers scheduled this season? He may even be needed as a scheduled 6th starter.