Gasol announced that he had chosen the Bulls on his Twitter feed Saturday.
It hasn't been easy. After meditating it a lot I've chosen to play with the Chicago Bulls. Looking forward to this new chapter of my career
- Pau Gasol (@paugasol) July 12, 2014
Discussions between Chicago and the Los Angeles Lakers on a sign-and-trade deal for Gasol broke down, so the four-time All-Star will sign directly with the Bulls, sources told ESPN.com.
Chicago currently does not have salary-cap space, so it will have to make roster moves to free room to add Gasol.
If the Bulls are unable to work a last-minute trade of Carlos Boozer, it likely means they will have to release him via the amnesty provision and clear the forward's $16.8 million off their salary cap to make room for Gasol. The deadline for such a move is Wednesday.
Boozer then would be placed on waivers and teams with cap space could bid to pick up a portion of his contract. The team with the highest bid would get his services. With so many teams currently owning cap space, it is doubtful Boozer would pass through and become an unrestricted free agent.
The Bulls are also hoping to create additional cap space to sign 2011 first-round draft pick Nikola Mirotic, who reached a buyout agreement with his Spanish team last week with the intention of coming to the NBA. The 6-foot-10 power forward has been seen as an offseason priority for the Bulls as they look to bolster a strong front line that already includes Joakim Noah and Taj Gibson.
Bulls rookie Doug McDermott, who heard the news through friends, said the atmosphere surrounding the team is exciting but "different."
"I'm not used to this situation," McDermott said. "All my buddies were texting me, 'I heard Pau was your teammate now' -- I didn't even know that. It's pretty cool, though. [The front office] is doing a great job with free agents, and I'm excited to be a part of that."
McDermott said Gasol would be an invaluable addition to the Bulls.
"I think it's huge for everyone," McDermott said. "He's so unselfish -- and a 7 feet can really pass the ball. So it can only help a guy like me where he'll be able to find me."
Gasol, one of the most coveted free agents on the market, was pursued aggressively by the San Antonio Spurs and Oklahoma City Thunder. He also had talks with the Miami Heat and Lakers, with whom he played six seasons and won two titles. Gasol averaged 17.4 points and 9.7 rebounds in 60 games for Los Angeles last season.
With Gasol's departure, Kobe Bryant is the only player remaining from the Lakers' 2010 championship team.
Chicago coach Tom Thibodeau declined to comment on Gasol's arrival until the deal becomes official.
ESPNChicago.com's Nick Friedell contributed to this report.