Dear John: With Jake Arrieta’s “slight hamstring pull,” are the Cubs dreaming if they think he will be back after missing just one start? — Thomas Thiel, St. Francis University.

Dear Thomas: Fortunately, any talk of missing one start has quieted and now the Cubs are looking for Arrieta, who last pitched 15 days ago, to return this weekend against the Brewers.

Perhaps they took note of the hard lesson the Yankees learned earlier this summer with CC Sabathia. Diagnosed with a moderate hamstring strain on June 13, Sabathia attempted to return after just three weeks. He couldn’t get out of the third inning in that July 4 appearance. He wouldn't pitch again until July 16. However, since then, he has been very effective.

Judging by the nature of your question, Tom, you know how vexing hamstring injuries can be and how frequently they recur. The culprit for that reinjury, all too often, is coming back too soon.

Sitting on the back of the thigh, the hamstrings are a complicated group of muscles. When the foot is not in contact with the ground, the semimembranosus, semitendinosus, and biceps femoris work together to bend the knee. When the foot is in contact with the ground, they help stabilize the knee and extend the hip, especially if the gluteal muscles — those on which we sit — are weak.

If the gluteal muscles are too weak, the quadriceps muscles — which straighten the knee — are too strong, and/or sprinting is not regularly practiced, then the hamstrings are more vulnerable.

Once hamstring injuries occur, according to a clinical commentary in the February 2010 issue of the Journal of Orthopaedic and Sports Physical Therapy, they will recur 33 percent of the time within a year. Just ask Miami Marlins infielder Martin Prado, who strained his right hamstrings in spring training and again on May 7. Did the damaged hamstrings ultimately contribute to the torn cartilage in his right knee that required July surgery, from which he is still recovering?

The JOSPT piece goes on to report that the danger of reinjury is particularly great in the two weeks immediately following a return to sport.

Sooner or later, however, one gets well and Arrieta will have ample opportunity to prepare for the playoffs. If his rehabilitation is managed properly, this entire episode won’t be remembered by season’s end.

According to that same JOSPT article, the average time for return to one's preinjury level of performance for a high — near the pelvis — hamstring strain, which involves tendon, is 50 weeks. For a purely muscular injury, it is 16 weeks.

That isn’t to say that Arrieta should be sidelined that long. While the Cubs are saying the injury is “mild,” they are not revealing whether the injury is near the pelvis, in the middle of the muscle or closer to the knee.

With adequate therapy and the wrapping skills of the Cubs’ athletic trainers, he should be able to pitch relatively soon. He just won’t be at 100 percent speed on the basepaths.

Consequently, Arrieta’s unusual — for a pitcher — ability to hit home runs will be particularly valuable in the coming weeks.

John Doherty is a certified athletic trainer and licensed physical therapist. This column reflects solely his opinion. Reach him at Follow him on Twitter @JDohertATCPT.