After Youkilis narrowly moved ahead last week, Teixeira, in his first year with the Yankees, has moved back to the top spot this week.
Youkilis led Teixeira by a miniscule 1,315 votes a week ago. Now, in the latest ballot update announced Monday, Teixeira has jumped ahead by 35,632 votes -- with a total of 1,561,292 -- as both bid for their second All-Star Game start at first base.
The field also includes another premier slugger in Justin Morneau of the Minnesota Twins, who is third in the voting.
Fans can cast their votes for starters up to 25 times with the 2009 All-Star Game Sprint Online Ballot at MLB.com and all 30 club sites until July 2 at 11:59 p.m. ET.
Starting rosters will be announced during the 2009 All-Star Game Selection Show presented by Chevrolet on TBS on July 5. Baseball fans around the world will then be able to select the final player on each team via the 2009 All-Star Game Sprint Final Vote at MLB.com.
And the voting doesn't end there. Fans will have the opportunity to participate in the official voting for the Ted Williams Most Valuable Player Award presented by Chevrolet at the Midsummer Classic via the 2009 All-Star Game Sprint MVP Vote at MLB.com.
The All-Star Game, which is set for July 14 in St. Louis, will be televised nationally by FOX and around the world by Major League Baseball International. ESPN Radio will provide exclusive national radio play-by-play, while MLB.com will offer extensive online coverage.
Red Sox left fielder Jason Bay continues to lead all outfielders in the voting. Bay has been Boston's best power hitter all season. Meanwhile, Red Sox center fielder Jacoby Ellsbury vaulted four spots to sixth place this week. Right fielder J.D. Drew -- the Most Valuable Player of last year's All-Star Game -- is 11th.
Dustin Pedroia, the American League's reigning MVP, continues to be second at second base to Ian Kinsler of the Rangers. Despite his recent slump at the plate, catcher Jason Varitek is second at his position, trailing Joe Mauer of the Twins.
Third baseman Mike Lowell is fourth behind Evan Longoria, Alex Rodriguez and Michael Young.
Though he hasn't played in a game since April thanks to left wrist surgery, Jed Lowrie has moved up to fifth place among shortstops.
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.