PHILADELPHIA -- Connecticut coach Jim Calhoun didn't coach the top-seeded Huskies against Chattanooga in their opening round of the NCAA tournament Thursday.

“Coach Calhoun has not been feeling well for the past several days, and it is best that he not coach the team today for precautionary reasons,” said University of Connecticut Director of Sports Medicine Dr. Jeff Anderson.

Calhoun Hospitalized, Misses Game 1 Students React To Calhoun Hospitalization

UConn said in a statement Thursday that Calhoun wasn't at Wachovia Center for the afternoon tip-off.

Connecticut coach Jim Calhoun hospitalized for tests, will be kept overnight for observation.

Anderson was with Calhoun at the team hotel, but the school did not say what was wrong with the coach.

"He's in the hospital," Associate Head Coach George Blaney said. "They plan to keep him overnight, but he expects to be with us shortly."

The coach ran UConn's practice Wednesday in Philadelphia, and attended the team's news conference.

"Jim was fine at dinner last night. He woke up this morning and didn't feel well," said Tim Tolokan, UConn's former sports information director and a close friend of Calhoun's.

Calhoun told Blaney he started feeling sick just before noon Thursday. He was brought to the University of Pennsylvania hospital for testing.

In a statement, Calhoun said the tests went well. He was released from the hospital Friday.

UConn basketball player AJ Price said wants Calhoun prowling the sidelines, not laying in a hospital bed.

"He was upbeat about everything and told us he couldn't wait to join us again, and we can't wait to have him," he said. "It'd be hard to not think about what would coach be doing right now and keep thoughts on game, but at this point in the year, it's what you gotta do."

Calhoun's son, Jeff, was at the Wachovia Center and said his father urged him to go watch the Texas A&M-BYU game, which the Aggies won 79-66.

Blaney took charge of the UConn team Thursday in Calhoun’s absence, leading the team to a 103-47 victory over Chattanooga.

CBS has reported that Calhoun's absence might last beyond this weekend.

Several UConn students said they were shocked by the news and wished Calhoun well.

"When you think UConn basketball, he's the founder," student Jonathan Grande said. "He's the big guy."

"I'm just thinking of him and praying that he does well and gets better because he is such a big part of UConn," said student Sarah Walberg.

"I'm kind of surprised because it's the tournament, so I'm sure it's serious," student Tim Troiano said.

"Hopefully he'll be back in a game or two," student Nick Pellon said.

Calhoun missed time in January 2008 with what the team called a combination of stress and exhaustion. The coach also said then he'd been suffering from a gastric problem, something he's had for years.

This is the third NCAA tournament game Calhoun has missed. In the two previous instances, UConn went on to win the national title.

In 1999, Calhoun missed a first-round game against Texas-San Antonio. In 2004, he left a second-round game against DePaul after becoming ill.

Calhoun has missed 21 games in his career, including one other game this season -- a Jan. 3 contest against Rutgers.

Last May, the Hall of Fame coach was treated for a second bout of skin cancer. He had surgery to remove a lump in the upper right side of his neck near the jaw line and underwent radiation.