I highly recommend this Wash Post piece by Eli Saslow about how Obama distanced himself from Blago over the years. It shows quite clearly that Obama was deeply wary of any direct contact with Blago, and not only since the election, but for about the last four years. For example:
Long before federal prosecutors charged Blagojevich with bribery this week, Obama had worked to distance himself from his home-state governor. The two men have not talked for more than a year, colleagues said, save for a requisite handshake at a funeral or public event. Blagojevich rarely campaigned for Obama and never stumped with him. The governor arrived late at the Democratic convention and skipped Obama's victory-night celebration at Chicago's Grant Park.Even though they often occupied the same political space -- two young lawyers in Chicago, two power brokers in Springfield, two ambitious men who coveted the presidency -- Obama and Blagojevich never warmed to each other, Illinois politicians said. They sometimes used each other to propel their own careers but privately acted like rivals. Blagojevich considered Obama naive and pretentious and dismissed his success as "good luck." Obama disparaged Blagojevich for what he viewed as his combativeness, his disorganization and his habit of arriving at official events half an hour late.
And more:
Blagojevich never endorsed Obama in his U.S. Senate bid in 2004, and he expressed a preference for two other Democratic candidates. On the campaign trail, Obama sometimes made a point to highlight his distance from Blagojevich and the rest of the administration. "Nobody sent me," he often told his crowds."The governor didn't offer his support, and to be honest, we didn't really ask for it," said Jim Cauley, a Kentucky native whom Obama hired to run his U.S. Senate campaign. "We weren't going to the old hall or chasing the county chairs. We wanted to show we weren't a part of that world."
While Obama prepared to deliver the keynote address at the 2004 Democratic National Convention, a speech that would launch him to stardom, Blagojevich was back in Springfield watching his own reputation dissolve. After a poor first term, he fought over the state budget with Democratic leaders before flying to Boston and arriving an hour late at a party held in his honor. The event was sparsely attended. Obama made only a brief appearance.
It notes elsewhere that Blago was pointedly excluded from all festivities at last year's Democratic convention in Denver. After you read this, it's not very hard to believe that Obama never spoke to Blago about the senate matter and that he directed his people to tread very carefully around the guv.