Messi is widely expected to stay at the Nou Camp just 12 months after he dramatically handed in a transfer request, with Messi understood to be ready to sign a new two-year contract.
But Barcelona president Laporta insists the club must respect UEFA's Financial Fair Play rules so cannot tie Messi down to a new deal yet, with the Catalans' chief confirming that the 33-year-old is helping the club out by taking a pay cut.
Laporta told the club's official website: "In economic terms, he has made it very easy, but Financial Fair Play is another battleground. We have to follow the rules, we will follow them.
"There will be more sales and loans. Without paying a transfer fee. We will do a lot of loans, because we have a very high sports payroll compared to other clubs."