Per veteran Houston radio host John Granato, the Toronto Raptors and Boston Celtics “are the favorites right now” to trade for disgruntled Rockets superstar James Harden. Granato has covered the Houston sports scene for decades, and certainly has his share of connections.

“It’d be a package for Pascal Siakam and more or Jaylen Brown and more,” tweeted Granato, who works with Houston’s ESPN Radio affiliate. He cited an “impeccable source” for that information.

Granato did not specify whether a trade might occur before the rapidly approaching 2020-21 regular season, or if the Rockets would put it off until later in the year — perhaps in hopes of eventually changing the All-Star’s mind about his ability to compete for an NBA title in Houston.

That said, if the Rockets trade Harden at some point, Granato’s report could have legs. In the last major update from ESPN’s Adrian Wojnarowski, Woj said Houston had expanded trade talks beyond Harden’s preferred destinations (Brooklyn, Philadelphia, Miami and Milwaukee).

Granato’s report would jive with that assessment. With Harden under contract for at least two more years, it’s possible a title contender could take the chance on making a deep playoff run in 2021 and/or 2022 and using that success to help sell Harden over time regarding a longer-term partnership.

But even if Harden were to eventually leave upon becoming a free agent, it would certainly be worth it if he brings that team a championship — as was the case for Toronto with Kawhi Leonard in the 2018-19 season. The Raptors could easily use that template again with “The Beard.”

From Houston’s perspective, Toronto and Boston could each make sense as a trade partner. All else equal, Rockets general manager Rafael Stone would likely prefer to send Harden to the Eastern Conference, as opposed to a direct competitor in the West. Among widely speculated Harden suitors in the East, only Philadelphia with All-Star guard Ben Simmons has a potentially superior trade asset to Siakam or Brown — and former Rockets GM Daryl Morey (now president of basketball operations with the 76ers) continues to insist that the 24-year-old will not be traded.

Over time, that could change. It might also be posturing. But if Simmons isn’t available, a package headlined by Siakam or Brown could potentially have the upper hand. Here’s how ESPN’s Tim MacMahon characterizes the asking price by the Rockets for Harden:

Houston has its heels dug in regarding Harden, refusing at this point to consider an offer unless it includes a young franchise cornerstone and a bundle of first-round picks and/or promising players on rookie deals.

Siakam, 26, was an All-Star last season. A 6-foot-9 forward, he averaged 22.9 points, 7.3 rebounds, and 3.5 assists in 35.2 minutes per game.

Meanwhile, the 24-year-old Brown had a breakout campaign, averaging 20.3 points (48.1% FG) and 6.4 rebounds in 33.9 minutes per game. The 6-foot-6 guard was the No. 3 overall pick in the NBA’s 2016 draft.

Perhaps most importantly, Siakam and Brown are each under contract for the next four NBA seasons. That would give the Rockets significant asset control, which is likely important if they’re going to give up a player as valuable as Harden, a perennial scoring champion and MVP finalist.

For any deal to get to the finish line, Houston would want other assets — such as future draft compensation and/or young prospects — in addition to Siakam or Brown. Both the Raptors and Celtics, who are each above the NBA’s salary cap, would also have to send out extra salary to be allowed to take in Harden’s $41.3-million figure for this season.

Simmons is certainly on the same playing field, and he is signed for five more seasons. But among the other three teams on Harden’s preferred list, the likely centerpieces of those bids (Miami’s Tyler Herro, Milwaukee’s Khris Middleton, and Brooklyn’s Caris Levert) don’t appear on the same level as Siakam or Brown when it comes to being a “young franchise cornerstone.” Middleton is 29. Herro isn’t anywhere near as proven, and Levert isn’t signed for as long a period moving forward.

If the Rockets eventually trade Harden, the 76ers still seem to be the safest bet, since they could give Houston satisfactory assets while providing Harden a team from his desired list. The Rockets could also explore three-team trade scenarios involving the other three teams on Harden’s list, if another NBA team is willing to give up a young cornerstone for one of those packages from the Nets, Heat or Bucks.

But if those four teams aren’t able or willing to meet Houston’s asking price, the Raptors and Celtics would certainly seem to have an opening. While the 31-year-old Harden is certainly older than Siakam or Brown and could potentially enter free agency sooner, that risk could be worth it, if a deal elevates either squad to a championship level. Just ask the Raptors about their recent experience with Leonard.