League sources told ESPN.com this week that the Spurs and Clippers have emerged as two more rivals for the Cleveland Cavaliers to worry about as the Cavs continue to try to lure Allen away from the Miami Heat.
Allen announced last month that he's still deciding whether he wants to play what would be his 19th NBA season, but that certainly hasn't done anything to limit interest in the 3-point specialist.
Clippers coach Doc Rivers is a natural Allen recruiter after coaching him in Boston. Despite possessing very limited financial flexibility, the Clippers have only 11 players under contract and certainly could use a shooter of Allen's caliber.
The Spurs, meanwhile, have only one open roster spot at the moment. As ESPN.com reported Friday, they have also registered interest in Mexico star center Gustavo Ayon while remaining hopeful of re-signing reserve center Aron Baynes, whom Australia is relying on heavily at the FIBA World Cup in Spain with Andrew Bogut absent.
The Cavaliers have been considered a strong favorite to land Allen league-wide since LeBron James decided to return to his home-state team in July. But the competition for Allen's signature is fierce.
The Dallas Mavericks, sources say, are yet another top Western Conference team to register interest in Allen this summer and there are believed to be more teams chasing him that have yet to be identified.
"It's August and I don't want to rush to judgment," Allen said earlier this month at the Jim Calhoun Charity All-Star Classic in Connecticut. "I want to get to September and see how I really feel."
Allen has been a member of championship teams in Boston (2008) and Miami (2013) and holds the NBA record for most 3-pointers made both in regular-season play (2,973) and the postseason (385).