The Lineup is here to dish out fantasy insight on all things baseball. Here are five storylines you should be following this week:

Fantasy owners hit the waiver wire in rabid form at the end of April when news came out that Atlanta Braves closer Bob Wickman had been placed on the disabled list with a bad back. Rafael Soriano and Mike Gonzalez were scooped up in leagues everywhere and the duo combined to convert all the save opportunities presented to them. The performance of both relievers, Soriano especially, should have caused the Braves organization to rethink its closer situation. However, according to The Atlanta Journal-Constitution, "Braves manager Bobby Cox didn't hesitate when asked Monday whether Wickman would resume closer duties [Tuesday] when he's scheduled to come off the disabled list. 'Yeah, why not?' Cox said. 'He's good.'" Despite the poignant words of Cox, fantasy owners should not assume that Wickman will be the closer from here on out. He has been great for the Braves since his arrival late in the 2006 season, but he will have to stay sharp and healthy to keep the job. Should Wickman struggle, Soriano is the immediate favorite to take over the role as Gonzalez is now on the DL with elbow issues — never a good sign. Soriano has filthy stuff and really should be groomed as the closer of the future for Atlanta. Monitor Wickman very closely this week and see if he has any problems reassuming the closer's role.

The Oakland Athletics have already endured their fair share of injuries thus far this year, but according to MLB.com, "For the ninth time this season, the A's on Tuesday were forced to use the disabled list, shelving closer Huston Street for a minimum of 15 days with irritation in his right ulnar nerve." Bad news for the A's who suddenly have a muddled closing situation. Set-up man Justin Duchscherer became the favorite to close games with Street out, but he is battling an arthritic hip and received a cortisone shot this past Thursday in an attempt to alleviate the pain. The Athletics expect Duchscherer to be ready for the coming week, but keep in mind that there was talk of a DL stint for him just a day before Street was placed on the disabled list. So who does that leave if Duchscherer ends up sitting for a prolonged period of time? Manager Bob Geren reveals that, "we'll mix and match with [Jay] Witasick, [Kiko] Calero and [Alan] Embree." Yikes. There is no point in owning Witasick, Calero or Embree if they are going to be used in a closer committee. The Lineup advises fantasy owners to snatch up Duchscherer if they have room on their roster and need saves, he would be worth owning if he can avoid the disabled list as he is a clear favorite for save chances. As for Street, it is hard to say how long he will be out. Both he and the A's are being relatively quiet about the injury. Fantasy owners should not cut Street just yet, but pay attention to any updates that come out regarding his condition this week.

Looks like fantasy owners are not the only ones miffed about Los Angeles Angels starting pitcher Ervin Santana's inconsistencies this season. According to The Los Angeles Times, "Santana does not appear to be on the verge of a demotion to Triple-A Salt Lake, but the Angels' patience with the 24-year-old righthander seems to be wearing thin." Santana has had pretty good strikeout numbers with 37 Ks in just under 48 innings. But the bloated ERA (5.51) and WHIP (1.56) have fantasy players everywhere pulling their hair out. Santana seemed like a pretty good sleeper pick coming into the season, but it has been a tale of two Santana's in 2007. At home, the talented youngster boasts a 2.57 ERA. But on the road, Santana has a Jeff Weaver-esque 7.86 ERA. Many of you have probably already cut ties with Santana and have relegated him to the waiver wire pile. The Lineup can't really blame you. With Dustin Moseley pitching well in relief and Joe Saunders ready to be called up from the minors, the Angels have the resources and flexibility to send the struggling starter to Triple-A. Ignore Santana for now and see what develops this week with the Angels rotation. Saunders or Moseley might be worth taking fliers on in AL-only leagues and deeper mixed formats if either of them gets the call to start.

Playing in what could be a very tight AL West, the Seattle Mariners have had a modest start to their 2007 season. Hovering around .500, this is a key week for Seattle to build some momentum. After playing a makeup game at Jacobs Field against the Cleveland Indians, the Mariners will continue their road trip in series' against a couple of perpetual cellar-dwellers in the Tampa Bay Devil Rays and Kansas City Royals. Outfielder Ichiro Suzuki is an obvious must-start this week despite some of his recent struggles. In the match-up against the Devil Rays, designated hitter Jose Vidro is a nice play as he possesses a career .356 average against them. First baseman Richie Sexson hopes to bust out of his early season funk against Tampa Bay, whom he owns a career .326 average against. Felix Hernandez, barring any health issues, is due up against the Royals and is a must-start. He's only faced the Royals once, back in 2005, but in that game he struck out 11 batters while allowing only 1 run in 8 innings. Third baseman Adrian Beltre flexed his muscles against Kansas City pitching last season as he hit at a .375 clip with 4 homers and 11 RBI; needless to say, fantasy owners should feel safe starting him. Similarly, two-bagger Jose Lopez also had success against the Royals in 2006, posting a strong .333 average. It should be a productive week for fantasy owners in possession of Mariner players, so take advantage.

The Boston Red Sox have had their starting rotation perform well enough thus far to keep the versatile Julian Tavarez in as their fifth starter. But he might not want to get too comfortable in the role as The Boston Globe revealed that, "[starting pitcher Jon] Lester will be restarting his rehabilitation, back to the minors on another 30-day rehab assignment. It will potentially get him that much closer to a spot in the Red Sox' rotation, a spot that's been on his mind for quite a while." Lester's 2006 season was cut short when he was diagnosed with anaplastic large cell lymphoma. Earlier this season, Lester left his first rehab start with pain in his left forearm and the Sox have been careful with the prized youngster since then, allowing him only to work out with the team before sending him back to Triple-A for rehab assignment. He still seems at least six-to-eight weeks away from the big leagues, but fantasy owners may want to track how he does this week and in the near future. With Josh Beckett's blister troubles looming as an issue again and Tavarez's name coming up in multiple trade rumors, it is not hard imagining Lester joining the rotation as soon as his rehab stint is completed. He showed some promise in 2006 and has been a highly touted prospect in the Red Sox organization for some time now. Lester would certainly be worth adding in fantasy leagues were he to join the starting rotation.