HOUSTON - Five days before the biggest game of Houston's season, Tom Herman summoned his quarterback, Greg Ward Jr., to his office. The head coach had a letter for him.

Around this time each year, the Heisman Trophy Trust mails letters to several of college football's top players, congratulating them on their seasons thus far and informing them that "the Heisman Memorial Trophy electorate ... has taken note of your consistently excellent performance." It doesn't mean the recipient should book a trip to New York City; it's simply an acknowledgement of a stellar season.

For the Leonard Fournettes or Derrick Henrys of the world, receiving such correspondence might be a foregone conclusion, an afterthought. For Ward, a generously listed 5-foot-11 signal caller from Tyler, Texas, it means more. But Ward didn't call anybody or tell his teammates. He instead returned to the Cougars' weight room and shoved the letter in his backpack without saying a word, even as backup quarterback Kyle Postma tried to steal a peek.

Ward is no fan of the publicity or attention that comes with success.

"It's not about me," he told a group of reporters just hours earlier Monday. "I don't think about it."

If the No. 24 Cougars (9-0) continue to win, Ward will have to work harder to stiff-arm the buzz. He's one of the biggest reasons Houston is the last undefeated Group of 5 team ahead of its top-25 clash with No. 21 Memphis (8-1) on Saturday night (7 ET on ESPN2).

Ward is second in the FBS in completion percentage (70.2), ninth in Total QBR (83.1) and 14th in passing efficiency (161.6). He leads FBS quarterbacks in rushing yards (822), is third among all players in rushing touchdowns (16) and is the only player nationally to average more than 200 passing yards and 90 rushing yards per game.

Not bad for a player who 14 months ago wasn't primarily a quarterback.

"He's an exceptional football player," Tulsa coach Philip Montgomery said. "He's kind of the key that makes them run."

Though he was a quarterback at John Tyler High School, Houston's previous coaching staff initially recruited him as a defensive back because of his size and speed. A stellar senior season (4,202 passing yards, 39 touchdowns, five interceptions) changed that. As a true freshman at Houston in 2013, he served as the Cougars' backup quarterback, receiver and punt returner.

Last season, Ward played receiver for the first month and didn't take significant practice reps at quarterback until then-starter John O'Korn struggled. After only a week of quarterback practice reps, Ward relieved O'Korn in a 17-12 loss to Central Florida. The next week, then-head coach Tony Levine named Ward the starter. Ward helped lead Houston to a 28-24 road win over Memphis and never looked back. The Cougars are 15-2 when he starts at quarterback.

Greg Ward Jr leads FBS quarterbacks in rushing yards. Derick E. Hingle/USA TODAY Sports

When Houston's current staff arrived, there was work to do.

"We had to teach him how to study [game film]," offensive coordinator Major Applewhite said. "'What am I looking for? Don't watch the play, don't be a fan. See the offensive set, see how the defense aligns to it. What are the pre-snap indicators? When are they moving? Are they starting to show? How can I get them to show?' Those are things we had to teach him and what we're still teaching him."

Ward's growth is evident. He reads defenses and understands coverage better. His touchdown-to-interception ratio is impressive (13-to-4), as is his completion percentage. His yards per attempt are up significantly (9.08 this season, 7.64 in 2014). He's completing a higher percentage of passes for 10 or more yards (49.4 percent), as well as first downs and touchdowns (54.9 percent) and third-down conversions (45.7 percent) than last season.

"I think he's progressed tremendously," Houston receiver Demarcus Ayers said. "[He's] willing to get better at the things he knew he wasn't good at. Just to see him grow as a passer has really helped us and made him more dynamic as a player for this team."

Applewhite walks a fine line between encouraging Ward to be patient in the pocket and not discouraging him from using his natural running ability. One sign of his progress as a passer came in Houston's 34-0 win over Vanderbilt on Oct. 31. The Cougars faced third-and-9 early in the second quarter and Vanderbilt rushed seven defenders. He stood firm in the pocket and endured a big hit just as he delivered a picture-perfect throw to Ayers in the back-left corner of the end zone for an 11-yard touchdown. Afterward, Herman called it "maybe the best throw of his career."

"He stood in there like a bona fide quarterback, delivered the football while he was getting hit," Herman said.

Occasionally, Applewhite organizes games of "QB Family Feud" in the quarterback meeting room, splitting the quarterbacks on each side of the room with a ball in the middle. The first quarterback to grab the ball can answer a question -- usually related to reads, checks or coverages -- and Ward is as competitive as any of them.

"You can see a normal, calm demeanor in a meeting just immediately turn into a fierce competitor," Applewhite said.

The coaches would like to see improvement in one specific area: weight. In July, Herman told Ward, "I'm not going to play a 179-pound quarterback in Division I college football. ... It's not fair to the team, knowing that you can't take a hit and survive for a 14-game season." Ward reported to training camp in August at 184 pounds. Applewhite estimates Ward lost some weight during the season, as most players do, but is "probably somewhere between 175-180, consistently." This offseason, Applewhite wants Ward to add enough to his frame that, on a bad day, he's 185 pounds.

"Even though we've come a long way there are still a million miles to go," Applewhite said. "We need to keep growing and developing."

The Cougars face their toughest opponent to date on Saturday. Though Memphis is coming off a loss to Navy, it has a win over Ole Miss and is 18-4 dating to the start of 2014. A win would put Houston at 10-0 and further its chance at a New Year's Six bowl bid, turning even more eyes to Ward, who needs signature wins against Memphis or Navy -- both ranked teams -- to further validate his status as a dark-horse Heisman candidate.

Ward's high school once produced a Heisman winner: Earl Campbell. Monday, a reporter asked Ward -- who admitted he dislikes cameras and microphones -- what it would mean to have his name in the Heisman conversation, like Campbell once did. Ward's answer: "I can't really think about it."

Ayers, Ward's roommate, said classmates recognize Ward on campus regularly, but the quarterback "has a knack for being focused and blocking out everything and going to class and trying to take care of business."

"I hardly ever see Greg on campus now, so whatever he's doing, he's probably hiding," Ayers joked.

If Ward keeps leading Houston to wins, it will be much harder to hide.