Goal revealed that the north London club have met the release clause in Marouane Fellaini's Everton contract, while they are also close to finalising a deal for Real Madrid striker Gonzalo Higuain.
|10/1||Arsenal are 10/1 with BetVictor to win the Premier League
"I think they need just two or three signings and they can challenge for the title," Seaman told Goal.
"When Arsenal play at their best, they are very hard to beat."
Seaman's claims support those of former team-mate Ray Parlour, who, speaking exclusively to Goal, urged Arsene Wenger to spend £100 million on Higuain, Fellaini and Wayne Rooney.
But Seaman does not believe new signings alone will re-establish Arsenal at the top of the table, and has urged the the club to change their wage policy to ensure their best players do not continue to leave.
"It is hard when you let your best players go," Seaman added. "Maybe [the club] could alter the wage structure [to prevent it]."