The optimal Red Sox lineup

Kevin Youkilis will return from his suspension on Tuesday in Toronto and bring with him one of the best bats in the Red Sox lineup. His return, though, will make things even more challenging for Red Sox manager Terry Francona in his effort to juggle playing time for the weapons at his disposal.

We can hold a few truths to be self-evident:

1. Jason Bay, J.D. Drew, Jacoby Ellsbury, Victor Martinez, Dustin Pedroia and Kevin Youkilis should be in the Red Sox lineup just about every single day.
2. Neither Alex Gonzalez, acquired Friday from Cincinnati, or Nick Green should be hitting higher than ninth in the lineup.
3. Casey Kotchman is a terrific defensive first baseman.
4. Red Sox pitchers, particularly Josh Beckett and Jon Lester, love throwing to Jason Varitek.
5. Mike Lowell and David Ortiz both are getting older and slower and bring varying degrees of effectiveness with the bat -- and both have significant numbers left on their contracts

The issue facing Francona right now revolves mostly around first base, catcher and designated hitter. Ortiz and Varitek each have a long history with Francona and with the Red Sox, but neither is swinging anything resembling a productive bat. Mike Lowell is swinging a hotter bat than anyone on the team but doesn't have adequate range to play third base every day. Casey Kotchman is a fairly average hitter but can really, really pick it at first base.

But with Victor Martinez an everyday presence, only two of the four can play every day.

Who should it be?

Here's how they stack up this year against lefties...
Lowell: .903 OPS
Varitek: .872
Ortiz: .720
Kotchman: .634

... and against righties:
Lowell: .818 OPS
Kotchman: .806
Varitek: .719
Ortiz: .696

It really is that simple.

Lowell should be DH'ing every day. Varitek should catch primarily against lefties and sit primarily against lefties, though his rapport with Josh Beckett and Jon Lester ought to have something to do with it, too.

Kotchman should sit against lefties and play against righties. Ortiz should be a formidable lefthanded bat off the bench who can give opposing managers pause when they're thinking about bringing in a right to face the bottom of the Red Sox lineup.

Youkilis will be back Tuesday. We'll see how Francona plays it.