Barcelona president Joan Laporta said the club are "out of the hospital" in terms of their financial situation as the LaLiga giants unveiled striker Robert Lewandowski at the Camp Nou in front of 57,300 fans.
"A year ago, sadly, we had to announce an unwanted situation as a result of the club's economic situation, but a year has passed and we can say that we are turning things around," Laporta said of the club's failure to register Messi's new contract with LaLiga last summer to comply with the league's financial fair play rules.
Laporta claimed in August that his board had inherited a club record debt of €1.35 billion but the sale of assets this summer has allowed Barca to spend over €150 million in the transfer window.
"It's been a very difficult year for us," Laporta said. "We've had so many big decisions to make and with a lot of pressure.
"A year later, we are turning the situation around. We have to continue to work. But we can say from a financial standpoint, we are out of the hospital. We still have to be cautious.
"Barca has brought in €800m in the past two months. We have made a great effort. We have had to sell some assets but we can get those back in the future.
"We are working to help Barca return to be a reference in football. We are getting back to the place we belong."
Despite the unveiling of Lewandowski, he is yet to be registered along with the other new signings.
"We have worked hard to register all of the players not just Robert," Laporta said. "It's a LaLiga decision and we are waiting. I think we have accomplished everything they have asked for. "
Ahead of Barca's league opener against Rayo Vallecano on Aug. 13, a fourth financial injection has been approved by the Catalan club should they need to use it to comply with the strict spending caps in LaLiga.
"Regarding the fourth financial injection [the sale of a further 24.5% of Barça Studios to the company Socios.com for €100m], it was something we had planned to do as a precaution just in case there is a difference of interpretation [with LaLiga]," Laporta added. "It has been approved by the club, but we hope we don't need to go through with it. If we have to use it, we will."
Despite the uncertainty around the registration of his new signings, Laporta beamed with pride when talking about Lewandowski.
"Today is a historic day for Barca," he said. "We are all excited that a player of Robert's calibre is here. We are on the right track. We see in the transfer market than players want to come and play at Barca.
"We wanted a top striker. If a genie came and gave us three wishes, we would have asked him for a scorer, one that has won the Golden Shoe several times and to be a goal guarantee. And that's Robert.
"There were many clubs that had offered Robert better financial conditions, but he chose to come to Barca and that is why I'm so grateful to him."
Barcelona endured a difficult campaign on and off the pitch last season but the Poland international said he is focused on enjoying a successful spell at Barca.
"When they explained the project, I knew I wanted to come," he said. "It's going to be a different season with respect to the last.
"It wasn't easy to leave Bayern after eight years but it's the perfect next step for me and my family. I was ready for this.
"This is a big challenge for me to be the best of Barcelona and to push other players to give their best with my huge experience. We have a lot of young players with huge potential, but the mix of youth and experience is important and if I can help them, I'm going to do it."
Lewandowski, who will turn 34 on Aug. 21, signed a four-year contract with Barca.
"I don't feel that I'm 33 or 34," he added. "I feel I can play at the top level for more years.
"Real Madrid did very well in the Champions League and LaLiga last season. We are there also to try to beat Real Madrid.
"I'm eager to play against them. But I'm not thinking of Real Madrid or rivalling Karim Benzema. He is an extraordinary player that has played many years in LaLiga. For me, it's important to play well with Barca."