Matsuzaka has had pinpoint control and filthy stuff over his last three starts, a span in which he's 3-0 with a 1.87 ERA.
Not that Matsuzaka will take much credit for his surge.
"I think it's really due to the fact that our lineup has been hitting really well and giving me the opportunity to pitch at my own pace," said Matsuzaka.
The three-start slump Matsuzaka had in late April and early May has become a most distant memory.
"He had a little bump in the road, as a lot of people do," said manager Terry Francona. "Some guys have it in August. He fought through it and worked hard. Now we're seeing the results of a lot of hard work and a really good pitcher."
Despite his recent success, Matsuzaka continues to seek ways to get better. He spent his side session making an adjustment to the grip on his changeup, a pitch that hasn't been as sharp over the last few weeks.
It was indicative of the overall approach of the Red Sox. Even though they have a 9 1/2-game lead in the American League East, there is no contentment.
"We just need to continue to work on this team, work on different things we need to work on," said catcher Jason Varitek.
The Red Sox had gone 8-0-1 in nine series before dropping two out of three in New York this week. Now the Sox will attempt to regain their groove against the Rangers, who are in last place in the AL West.
Nobody comes into this series hotter than first baseman Kevin Youkilis, who has a career-high hitting streak of 16 games and is batting .347.
BOS: RHP Daisuke Matsuzaka (6-2, 4.06 ERA)
Matsuzaka is on fire. In his last two starts, he hasn't walked a batter, and he has lowered his ERA from 5.45 to 4.06 in a span of three starts. He is holding opponents to a .235 average. This will be Matsuzaka's first career start against the Rangers.
McCarthy is 3-0 with a 2.31 ERA in his last four games, holding opponents to a .202 batting average. That's a complete turnaround from April, when he was 1-4 with a 9.90 ERA, and opponents hit .356 off him. The big difference has been putting his fastball where he wants it, using his changeup effectively and making adjustments quickly before innings get out of control. He is 2-1 with a 6.23 ERA in three starts at home this year. He is 1-1 with a 2.03 ERA in four games, including one start, in his career against the Red Sox.
Player to watch
Youkilis is hitting .405 in May, with four homers and 17 RBIs.
NESN On radio
WRKO-680 AM, Spanish Baseball Network Up next
Saturday: Red Sox (Tim Wakefield, 4-5, 3.14) at Rangers (Vicente Padilla, 2-6, 5.52), 8:05 p.m. ET
Sunday: Red Sox (Julian Tavarez, 3-4, 5.27) at Rangers (Kameron Loe, 1-4, 6.38), 3:05 p.m. ET
Monday: Indians (TBA) at Red Sox (Curt Schilling, 4-2, 3.94), 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.