This is not what Conner Preston envisioned for the 2013 season.

After a redshirt freshman season last year as Garrett Gilbert’s backup, Preston was planning to spend one more year as the SMU Mustangs’ No. 2 quarterback — ready to step in for Gilbert, if needed, mop up lopsided games and sharpen his command of the offense in the hope of taking over the starting role, or at least competing for it, in 2014.

SMU quarterback Conner Preston chose a regimen of therapy over surgery to recover from TOS (photo by Doug Fejer).

But the plan went awry during the Ponies’ spring workouts. Preston’s spring was cut short because of discomfort under his left shoulder, the origin of which is not exactly clear.

“I took a shot, maybe in the Stephen F. Austin game — we’re not sure,” Preston said. “You know how some people, when they work out, they get these big veins that stick out of their muscles? Well, that’s not me. I’m not a very ‘veiny’ person, but this spring, when I worked out, I had these big veins sticking out. I started to look like those people, almost like I was taking steroids or something. I was so pumped up. I have a vein under my left arm that really bulged out, and then my left hand started to go numb during workouts.

“I’m not one to immediately go to a doctor, and I went through all of the offseason workouts (after the team’s spring workouts). Eventually, I saw some doctors, and found out I have Thoracic Outlet Syndrome — TOS.”

TOS is defined by medicinenet.com as “a condition whereby symptoms are produced from compression of nerves or blood vessels, or both, because of an inadequate passageway through an area (thoracic outlet) between the base of the neck and the armpit.”

“It was weird,” Preston said. “It happened (under) my ‘off’ (non-throwing) arm. One wanted to operate on my left arm, and that would have been three to four months for recovery … and that was in May, so it would have been August, or probably September, at the very earliest before I’d be ready to come back.

“Then it started in my right arm, too. Some people are born with an extra rib, and when that happens, they can do surgery to take out that extra rib. I’m not one of those people — I don’t have that extra rib. So I found one doctor who wanted to take out my top rib on one side, and then three or four months later, take out my top rib on the other side. That sounded pretty serious to me. We would be looking at six to eight months and a rib missing from each side.”

In lieu of surgery, Preston consulted with another doctor who recommended a series of exercises designed specifically to help alleviate the construction of the muscles in the thoracic outlet.

“I’m working out every day with (SMU strength and conditioning coach) Mel (de Laura),” Preston said. “You’ll never see me working out with a long barbell, because when you lift a full bar, one arm can overcompensate for the other. I only lift with dumbbells, because the muscles in each arm to do what they’re supposed to do, independently of the other. It’s supposed to open up that muscle area.”

Preston said that before settling on his physical therapy routine, he sat down with SMU head coach June Jones and associate head coach/offense Dan Morrison to discuss his health and his future.

“We sat down and talked about it,” Preston said. “I could have done surgery and been done with it, but again, if they took ribs out, that’s pretty serious. I went with the therapy because by doing that, I can be as strong as ever, not worse, in three to five months.

“So I started the therapy in June, which means I guess I could be back as soon as mid-October. Or, it might take longer — we really don’t know. But this will get me back, strong, and without surgery.”

For the time being, Preston is helping with the offense in practice and holding for placekicks.

“(Preseason) camp just started,” Preston said when asked how it feels to be watching his teammates practice work out instead of being on the field with him. “I haven’t really had time to reflect on that.

“Garrett (Gilbert) is the starter, anyway. If I were the starter this year, maybe I would look at the quicker surgery option. But the way my status is on the team, it’s better for my health, long-term.”

Preston said that TOS has been tough, but that he fully intends to rejoin his teammates as quickly as possible.

“This is the fun time of the year,” Preston said. “This is what you work for when you work in the offseason — getting back on the field. My main focus is handling this properly and getting back out there as soon as I can.”