After participating in a light walk-through practice on Wednesday morning with his teammates, Harvin wasn't present for the full afternoon practice. Head coach Leslie Frazier declined to go into detail on Harvin's absence and said he wasn't sure if one of the team's most important players would be around for the final day Thursday.
"We're going to talk more in detail," Frazier said. "We have a lot of things to talk about."
Earlier Wednesday, Spielman refused to confirm that Harvin had requested a trade, as sources have confirmed to ESPN.com's John Clayton, but made it clear it would be a moot point regardless.
"We drafted Percy Harvin here," Spielman said. "He's a key part of our organization. He's a key part of our football team. Any issues that are out there or reported, we always handle those internally and continue to handle those internally."
Spielman wouldn't shed any light on what Harvin said were multiple issues that have upset him this offseason. But Spielman did say he has spoken with Harvin's agent, Joel Segal.
Harvin voiced frustration with the Vikings on Tuesday at the first day of mandatory minicamp. He did not say what his specific issues were with the team, only saying he was unhappy with several things and wanted them addressed before training camp begins at the end of July.
"I just put it this way: There's a lot of different things that have to be sorted out," Harvin said Tuesday. "Just haven't been really happy lately. We've got a couple of things to work on. I'm here in the classroom. We'll go from there."
Harvin is due to make $915,000 in the fourth year of a five-year rookie deal. That total is much lower than veterans Michael Jenkins and Jerome Simpson, with neither coming close to his production on the field.
Spielman would not say if money was an issue, but also reiterated the organization's approach to signing players to extensions.
"Our philosophy has always been as players enter the last year of their contract, we have a history of extending players going into the last year of their contract," Spielman said. "And that's been our history."
Harvin took to Twitter on Wednesday night to address the issue, but would only say that it was not related to money.
"Fans I said I have issues to be worked out money not at all being the problem...I've dne everything asked and more...," he wrote.
Harvin left the practice field Wednesday morning before reporters could ask any questions. Running back Adrian Peterson said he hadn't spoken to his friend about it but planned to have a conversation to try to help smooth things over.
"I wouldn't say it's distracting. It's more bothering. It's like, we definitely don't want to lose this guy. ... I'm sure the organization will do what it has to do to keep this guy around," Peterson said. "If it was me, I would make sure that we kept him around. But we'll see."
Harvin, who is recovering from offseason shoulder surgery, said Tuesday he did not want to be a distraction and would only talk about football issues.
He has two years left on his rookie contract, but it was not immediately clear how much that had to do with his displeasure, if at all. The Vikings are coming off consecutive last-place finishes in the NFC North and have entered a rebuilding phase centered on Harvin, Peterson, who is recovering from a torn ACL, and second-year quarterback Christian Ponder.
Harvin was the team's first-round draft pick in 2009 and quickly has emerged as perhaps the team's most versatile and dynamic player. He is the team's only proven commodity at receiver heading into his fourth season and is coming off a year in which he posted career highs in receptions (87), yards (967) and total touchdowns with nine.
Harvin has shown the ability to play in the slot as an inside receiver, on the perimeter as a deep threat and has become one of the most dangerous kick returners in the league. He also rushed for 345 yards last season, helping to spell Peterson in the run game.
"Percy is a phenomenal player on the field," Spielman said. "And you look at his statistics he had last year and how important he is to this franchise. He's a vital part of us moving forward with this team."
Migraine headaches and a few other bumps and bruises from Harvin's physical and punishing style of play led to some concerns about his durability, especially in his first two seasons. But Harvin played in all 16 games last year while fighting a painful rib injury and became a respected veteran in the locker room.
His role in the offense could be an issue. Despite being used in a variety of roles last season, Harvin often found himself on the sideline in the red zone. The Vikings could be using more two tight end formations this year with the addition of pass-catching tight end John Carlson to go along with Kyle Rudolph.
Offensive coordinator Bill Musgrave said he wasn't aware of any issues Harvin had with the offense and pledged to use him even more this season.
"We're looking forward to getting him on the field and as an offense we're looking forward to having a better year," Musgrave said. "That's the bottom line."
Frazier said the two sides have to get on the same page by the time the team reports to Mankato for camp on July 26.
"Hopefully, we'll be headed in the right direction when we get to training camp and everyone can focus on getting ready for the Jacksonville game," Frazier said. "That's the way it has to be. We can't afford any outside distractions."
Information from ESPN.com NFC North blogger Kevin Seifert and The Associated Press was used in this report.