Question: Before playing in the NFL, Alejandro Villanueva was a member of which elite rapid-deployment military formation of the United States Army?

Context paragraphs:
United States Army Forces in the Far East: United States Army Forces in the Far East (USAFFE) (Filipino: "Hukbong Katihan ng Estados Unidos sa Malayong Silangan/HKEUMS") was a military formation of the United States Army active from 1941 to 1946.  The new command's headquarters was created on 26 July 1941, at No. 1, Calle Victoria, Manila, Luzon, the Philippines, with General Douglas MacArthur as commander.  The Chief of Staff was Brigadier General Richard K. Sutherland and the Deputy Chief of Staff was Lieutenant Colonel Richard J. Marshall.  The core of this command (including MacArthur, Marshall, and Sutherland) was drawn from the Office of the Military Advisor to the Commonwealth Government.

United States Army Rangers: The United States Army Rangers are an elite rapid-deployment military formation of the United States Army, that serve in designated U.S. Army Ranger units or are graduates from the U.S. Army Ranger School.  The term "ranger" has been in use unofficially in a military context since the early 17th century.  The first military company officially commissioned as rangers were English soldiers fighting in King Philip's War (1676) and from there the term came into common official use in the French and Indian Wars.  There have been American military companies officially called "Rangers" since the American Revolution.

Charles W. Bagnal: Lieutenant General Charles Wilson Bagnal (April 15, 1934 – June 30, 2015) was a United States Army officer.  He was commander of the United States Army Western Command (later United States Army Pacific), from 1985 to 1989.  Previously he was Deputy Commanding General for Training of the United States Army Training and Doctrine Command (TRADOC), Deputy Superintendent at the United States Military Academy (from 1977 to 1980), Commander of the 101st Airborne Division (1981-1983), Commander of the Officer Personnel Management Directorate for the United States Army Military Personnel Center, and Special Assistant to the Deputy Chief of Staff for Personnel.  He is an alumnus of the United States Military Academy, United States Army Command & General Staff College, Georgia Tech, the United States Army War College and McLenaghan High School in Florence, South Carolina (class of 1952).  He retired August 31, 1989, and later obtained his juris doctor from the University of South Carolina and practiced law.  He resided in Columbia with his wife Patsy.  Bagnal died on June 30, 2015 after a battle with leukemia.

United States Army Central: The United States Army Central, formerly the Third United States Army, commonly referred to as the Third Army and as ARCENT is a military formation of the United States Army, which saw service in World War I and World War II, in the 1991 Gulf War, and in the coalition occupation of Iraq.  It is best known for its campaigns in World War II under the command of General George S. Patton.

Army of Missouri: The Army of Missouri was an independent military formation during the American Civil War within the Confederate States Army, created in the fall of 1864 under the command of Maj. Gen. Sterling Price to invade Missouri.  Price's Raid was unsuccessful, and his army retreated to Arkansas, where it was broken up and absorbed into the Confederate Army of the Trans-Mississippi.  After the war, Price, accompanied by his subordinate Brig. Gen. Jo Shelby and several members of his former command, relocated to Mexico where they unsuccessfully sought service with the Emperor Maximilian prior to returning to civilian life in the United States.

Alejandro Villanueva (American football): Alejandro Villanueva (born September 22, 1988) is an American football offensive tackle for the Pittsburgh Steelers of the National Football League (NFL).  Villanueva was a Captain in the United States Army, in which he served as an Army Ranger and was decorated with a Bronze Star for valor.  He played college football for the Army Black Knights, being recruited at one position and playing three others during the course of his career.  After serving three tours of duty in Afghanistan, he signed a contract with the Philadelphia Eagles on May 5, 2014, after working out in a regional showcase.

Detroit Light Guard: The Detroit Light Guard is a military formation in the United States Army, Michigan Army National Guard that has served in many functions since its creation in 1830, including state duties, and even overseas combat.  It is survived today in the US Army's 1225th Corps Support Battalion.  The Light Guard's nickname, the "Tigers," is the origin of the name of the Detroit Tigers baseball team.

CENTAG wartime structure in 1989: The Central Army Group (CENTAG) was a NATO military formation comprising four Army Corps from two NATO member nations comprising troops from Canada, Germany and the United States.  During the Cold War, CENTAG was NATO's forward defence in the southern half of the Federal Republic of Germany (FRG).  The northern half of the FRG was defended by the four Army Corps of NATO's Northern Army Group (NORTHAG).  During wartime, CENTAG would command four frontline corps (II German, III German, V US, and VII US).  Air support was provided by Fourth Allied Tactical Air Force.

Civil Affairs Staging Area: The Civil Affairs Staging Area (CASA) also known as the Civil Affairs Holding and Staging Area was a combined U.S. Army, U.S Navy military formation authorized by the Joint Chiefs of Staff on June 18, 1944 during World War Two for military government theater planning, training and provision of military government personnel to areas of the Far East liberated from the Empire of Japan, including East China, Formosa and Korea.  CASA had two divisions: The Operations and Training Division focused on language instruction and execution of civil affairs duties at a local level.  These duties varied greatly and, as an example, included mass feeding of civilians, camp sanitation, provision of medical supplies, containment of epidemic diseases, labor relations and rodent control.  The Theatre Planning & Research Division developed plans for military government at a national level such as control of Japan's economic institutions, control of Japan's education system and methods for increasing the overall supply of food throughout, not only Japan, but also previously occupied areas like East China.  CASA provided comprehensive training and planning in civil affairs administration to officers coming from six schools of military government established at various universities throughout the United States.  Army & Navy personnel trained by CASA numbered in the thousands, with more than 1,000 officers assigned to a wide variety of civil affairs positions for the initial occupation of Japan alone.  The goal of the U.S. Army's Civil Affairs Division in the creation of CASA was to replicate the same success in the Far East experienced by the Civil Affairs Division in the European Theatre.  General John H. Hilldring ordered Colonel Hardy C. Dillard, Commander of the Civil Affairs Training Division for the European Theater of Operations, to take command of CASA from Colonel William A. Boekel and implement the European Civil Affair's planning and training program.  Colonel Dillard was relieved of command on 20 July 1945 by Brigadier General Percy L. Sadler.

The Alabama Brigade (American Civil War): Also known as Law’s Brigade, the Alabama Brigade was a military formation of the Confederate States Army during the American Civil War.  It was created in 1863 and participated in major combat operations such as the Battle of Gettysburg, the Battle of Chickamauga, the Battle of the Wilderness and the Richmond-Petersburg Campaign.  It was considered one of the great fighting brigades of the Army of Northern Virginia.

Supporting paragraphs: Alejandro Villanueva (American football) United States Army Rangers
Answer: United States Army Rangers