On Saturday night, the third-year sophomore will have a different view.
Carlisle transferred from USC to Notre Dame after the 2011 season. He is the third-leading rusher for a Fighting Irish team seeking to end USC's streak of five consecutive victories at South Bend, Ind.
Carlisle is looking forward to playing against his friends and former teammates in the 85th meeting between the historic rivals.
"It definitely will be weird," he said during a phone interview Wednesday. "But on the field it will be all business."
Transfers between USC and Notre Dame are rare in football. According to USC's sports information office, Trojans receiver Speedy Hart, a 1980 letter winner, halfback Ted Tannehill (1945-47) and halfback Harry Welch (1951-52) transferred from Notre Dame to USC.
School officials said Hart was believed to be the only player from either school to play for both the Trojans and the Fighting Irish in the rivalry game that dates to 1926.
The 5-foot-10, 190-pound Carlisle will probably add his name to history on Saturday.
Carlisle was Notre Dame's leading rusher after two games, but opportunities have been fewer since he fumbled against Purdue on Sept. 14.
George Atkinson III is Notre Dame's leading rusher with 323 yards and two touchdowns, and Cam McDaniel has a team-leading 63 carries for 259 yards and two touchdowns.
Carlisle has rushed for 178 yards in 38 carries and has seven receptions.
"He started off really well, and then we just had some other guys that have played well," Notre Dame Coach Brian Kelly told reporters Tuesday.
But Kelly acknowledged Carlisle's ties to the Trojans with USC coming to town.
"You can see he's pretty focused this week," Kelly said, adding "So we'll be keenly aware of his want to play very well against USC."
Ed Orgeron, USC's interim coach, indicated that Carlisle did not receive any extra attention in the Trojans' Notre Dame scouting report.
"I remember him being a great young man," Orgeron said. "I thought he was going to be an excellent player here."
Carlisle came to USC from King's Academy in Sunnyvale, Calif., where he rushed for 2,110 yards and 28 touchdowns as a senior. He chose USC over Stanford and Notre Dame and was part of a recruiting class that included receiver Marqise Lee and tailback Javorius Allen, who scored two touchdowns last week against Arizona.
"He was cool," Allen said, "and a great player."
Carlisle was slowed by ankle and knee injuries during his freshman season, but he played in eight games. He rushed for 118 yards in 19 carries and caught seven passes, including one for a touchdown against Colorado.
But Carlisle said family circumstances and "God's plan" led to his transfer.