Left-handed hitters David Ortiz and J.D. Drew were both out of the lineup.
"This guy makes you do this," said Francona. "This is our best chance to win the game. You look at the lineups he faces, I bet you it's not very often where he faces a team's best lineup. This is one of the few guys in the league where you have to make an adjustment because he's so dominating against left-handers."
Entering this one, Johnson had held lefties to a .154 average this season.
Wily Mo Pena got the start in right field. Kevin Youkilis and Mike Lowell, who both got one day off so Ortiz could start at first base in the first two games, were at the corners.
Never did the switch-hitting status of Coco Crisp and Jason Varitek come in handy more than Sunday, when both men could simply go to the right side against the Big Unit.
Daisuke Matsuzaka didn't exactly have an enviable matchup for his first game as a Major League hitter.
"I asked him if he wanted to hit cleanup," said Francona. "He looked at me and said, 'Randy Johnson, no, no.' This might not be a true test of his hitting prowess."
Meeting with Lester: Francona wasn't all that alarmed by Jon Lester struggling in his rehab outing on Saturday, when the lefty threw 70 pitches over just 2 2/3 innings.
"Physically he's fine and he felt real good," Francona said. "I don't think he was too pleased with his mechanics. You know what? Myself included, we can't forget that because of what he's been through and the rehab, all of a sudden he doesn't get people out and it's like, ['Whoa.'] He just had a tough outing."
Lester will likely pitch at Pawtucket in a start against Richmond on Thursday. His 30-day rehab stint expires on June 18. At that point, the Red Sox will either have to activate him or option him to Triple-A Pawtucket.
"We have never, ever put a time-table [on Lester's return]. Everyone had written that Julian Tavarez wasn't going to start past May 8 or whatever," said Francona. "This is a long-term commitment with this kid."
Julian's versatility: Though Tavarez has certainly been holding his own in the No. 5 spot in the rotation, Francona said that won't have a lot of bearing on when Lester is re-inserted into the rotation.
"We'll take good pitchers everywhere," Francona said. "One of the things he can do, which is amazing to me, is he can start, you can put him in the bullpen for a month, and if something happens, you could probably put him back in the rotation. I don't know how many guys you could do that with. It doesn't complicate it, it's very good."
Coco un-crisp at plate: Crisp continues to search for a sustained groove offensively. Perhaps one sign of Crisp's confidence level was reflected in him laying down a bunt on a 3-1 pitch in Saturday night's game. For a fastball hitter such as Crisp, it was a telling strategy.
"I agree that 3-1 is probably a time to get a nice fastball, which most hitters, including Coco, are probably looking for," Francona said. "It was bang bang. If he was safe, [the media is] going to say, 'that's good baseball.' You just try to keep it in perspective. I like the idea that he's trying to get on base because it's David hitting behind him. But it's also a very good hitting count."
Crisp entered Sunday's game in a 2-for-20 slump during the road trip, which has dropped his average to .224.
"The last little while, he's been leaving the strike zone quite a bit," Francona said. "He'll get that pitch in the zone and he'll hit it pretty hard. But they've been elevating on him, and he's not been staying in the zone enough where he can get hot."
On deck: Following Monday's off-day, Tim Wakefield (5-7, 4.22 ERA) will open up a six-game homestand against the Rockies on Tuesday night at Fenway. Colorado counters with Aaron Cook (4-2, 4.54). First pitch is scheduled for 7:05 p.m. ET.
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.