Arsenal ace Fabregas and Liverpool midfielder Mascherano have been both linked with the European champions, who are aiming to beef up their squad with new signings this summer.
The Premiership clubs, however, are determined to keep hold of their influential players, and have already rejected all bids made for their services.
Barcelona, who claimed a treble of trophies last term, are planning to repeat their feat next season, and Messi believes the duo would help the Catalans accomplish their objective.
"We were spectacular last season and we hope that this term, we will be able to do the same, or at least repeat a little of what we achieved," Messi told Sport.
"We were surprised by what we did last season but if players such as those who have been mentioned in the press arrive at the club to strengthen the team, it would be even better because it is important to be stronger.
"I hope Mascherano can come and we can form a solid partnership. His qualities are always appreciated.
"The same goes for Fabregas. A good footballer like him who can contribute a lot is always welcome."