Basically, if I have to give a one line answer: Glutamine will help your muscle recover much faster, and won't let you loose muscle easily. So, no it won't help your performance.
However this read might be interesting.
Based upon BodyBuilding site, which I totally second upon here are essential things about Glutamine:
What Is Glutamine?
Glutamine is created in the human body when the non-essential amino acid glutamate (or glutamic acid) is broken down and binds with nitrogen-containing ammonia molecules. Think of glutamine as a kind of nitrogen sponge. It mops up ammonia and shuttles nitrogen between tissues, where it can be used for cell growth and tissue repair, among many other functions. It's been reported that some 30-35 percent of all nitrogen derived from protein breakdown is transported in the form of glutamine. Glutamine can also be broken down to re-synthesize glutamate, which makes glutamine a critical source of ammonia and nitrogen.
Approximately 70 percent of your body's internal glutamine is produced in skeletal muscle, from where it travels to the small intestine, kidneys, and white blood cells. These are the dominant sites of glutamine usage.
Internal levels of this amino acid depend on various factors. Pregnancy and lactation significantly deplete the body's glutamine stores, as do exhaustive exercise, illness, disease, starvation or fasting, rapid growth and development, and other conditions of extreme physiological stress. These are some of the conditions where increasing your glutamine intake or considering supplementation is appropriate.
What Does It Do?
Glutamine—like other alpha-amino acids—is involved in regulating protein synthesis and breakdown. However, there's far more to it than that. Glutamine significantly affects BCAA metabolism, gut barrier maintenance, normal immune function, glucose formation, water transport, neurotransmission, and more.
Your kidneys are a primary consumer of glutamine use that's where the ammonia cleaved from glutamine works to maintain your body's acid-base balance. Anywhere you find ammonia, you'll find glutamine. As metabolic acidosis increases—as in response to intense training or a high-protein diet—renal uptake of glutamine soars. In fact, one study found that just four days of a high-protein, high-fat diet, was enough to cause a 25 percent drop in glutamine levels in the plasma and muscle tissue.
If all of these competing uses begin to outpace your body's ability to produce glutamine, then you may start to show signs of deficiency, including muscle wasting, depleted energy, and increased susceptibility to infections.
What Are the Performance and Physique Applications?
Despite glutamine's various functions, little evidence suggests it will directly result in increased muscle mass, reduced body fat, or gains in muscle strength or power in normal, healthy people. However, given how stressful intense training is on the human body, athletes may see certain benefits from supplementing with significant levels of glutamine, or from stacking it with other supplements.
One study found that when athletes suffered from mild dehydration, supplemental glutamine increased exercise performance and enhanced fluid and electrolyte uptake when combined with a glucose and electrolyte beverage. Supplementation has also been shown to raise levels of growth hormone in response to cycling to exhaustion.
Extracellular concentrations of glutamine have also been shown to activate the signaling pathway mTOR, which is known to be responsible for increasing muscle size. However, here again, the benefits of glutamine supplementation required that other conditions be met: in this case, mTOR signaling appeared to require the presence of BCAAs (leucine, most importantly), as well as some threshold level of cellular hydration.
In another case, collegiate track and field athletes who consumed four grams of glutamine per day for eight weeks, along with a loading and maintenance dose of creatine, saw greater gains in lean body mass than those who used creatine alone. This may sound significant, but it's hard to draw conclusions over a mere eight weeks at such a low dosage. Whether higher doses or a longer study would have resulted in significant differences is anyone's guess.