Miles finished with 14 points on 5-of-11 shooting and knocked down two of his four 3-point attempts. But he said the nature of the loss made his performance impossible to evaluate.
"Too many turnovers," said Miles, who finished with four.
He replaced rookie forward Gordon Hayward, who replaced Andrei Kirilenko last Saturday during a road loss to Philadelphia.
Miles has been Utah's premier scorer off the bench this season and is enjoying a career year. Sloan had been hesitant since training camp to change Miles' role, but he made the move Tuesday in the hope that he could spark a struggling Jazz squad.
Sloan is not sure whether the move will last, though, and he acknowledged following a Tuesday morning shootaround that he is experimenting with rotations.
He also joked that the media made the decision for him to suddenly start Miles.
"[The coaches] never talk about anything," a straight-faced Sloan said. "It's always amazing."
Miles ranked fourth on the team in average points (11.9) heading into Tuesday's game, while recording 3.1 rebounds and 1.6 assists per game. He was shooting 41.8 percent from the field and 33.5 percent behind the 3-point line.
But he asserted that his promotion is useless unless he and his teammates improve their effort and overall performance.
"We know that we can't push the panic button on ourselves," Miles said. "We can't jump off the [band]wagon. We can't decide that, 'OK. We're losing. I'm just going to get mine.' "
As for the public perception of Sloan that he avoids change at all costs?
That started "a long time ago" when he did not play rookies. But he pointed out that he started Shandon Anderson, a former Jazz small forward who played for Utah from 1996-99 and was the 54th overall pick of the 1996 NBA Draft.
"I don't really care what they have to say about me," Sloan said. "I screw up, I screw up. I'm not infallible."
Jazz reserve center Francisco Elson (left quadriceps tendinitis) returned to the active lineup Tuesday despite not being 100 percent and still dealing with pain.
Elson is using rest, treatment and anti-inflammatories to treat his injury.
"The season's going," said Elson, who totaled three points in 13 minutes against the Lakers. "You can't take a rest."
Utah reserve center Kyrylo Fesenko did not play due to an upper respiratory infection.
Spurs at Jazz
O At EnergySolutions Arena
Tipoff • Wednesday, 7:30 p.m. TV • FSN Utah, ESPN
Radio • 1320 AM, 1600 AM, 98.7 FM
Records • Spurs 38-7, Jazz 27-18
Last meeting • Spurs, 94-82 (Nov. 19)
About the Spurs • San Antonio has won 9 of its last 10 contests. … The Spurs rank fifth out of 30 teams in average scoring (104.1), fourth in assists (23.2) and seventh in rebounds (43.2).
About the Jazz • Utah has lost five consecutive games for the first time since Dec. 4-14, 2007, when it dropped six straight.