Five reasons for Nets' four-game skid

The Brooklyn Nets got off to an 11-4 start but since then have lost a season-high four straight games heading into Tuesday night’s game with the rival New York Knicks.

Why have they been struggling? ESPNNewYork.com examines five reasons:

1. Their center is out

The Nets are 1-4 since Brook Lopez went down with a mild right foot sprain -- the lone victory coming against the hapless Orlando Magic. I’m not sure anyone realized just how valuable Lopez is until he got hurt. The 24-year-old center, who has been playing at an All-Star-caliber level, is worth so much more than his 18.5 points per game (on an efficient 53.4-percent shooting). His mere presence on the court allows his teammates to thrive, whether it be by drawing double-teams that lead to open shots or protecting the paint against drivers (2.5 blocks). When Lopez was healthy, the Nets had a consistent rotation coach Avery Johnson felt very comfortable with. Things haven’t been the same without him. Lopez is officially listed as a game-time decision for Tuesday night’s game.

2. Their defense has regressed

According to ESPN Stats & Information, the Nets are allowing 11.5 more points per game (102.2 as opposed to 90.7) and their opponents are shooting 50.7 percent from the field during Lopez’s absence. They had been giving up 44.9 percent shooting during the first 14 games with Lopez in the lineup. Andray Blatche has filled in well for Lopez on the offensive end (17.2 points, 9.8 rebounds in four starts), but it’s the defensive end where Blatche struggles (0.4 blocks). The Nets need Lopez to once again be the man in the middle when he returns. Brooklyn has fallen to 19th in the league in defensive efficiency, allowing 103.2 points per 100 possessions.

3. Their bench hasn’t been as productive

At full strength, Johnson was using a second unit -- known as “The Bench Mob” -- that featured reserves Blatche, Reggie Evans, Jerry Stackhouse and C.J. Watson, with Joe Johnson serving as the anchor. But because of Lopez’s injury, Brooklyn’s rotation has been disrupted. Stackhouse is shooting just 30.4 percent in his past three games. Watson is averaging 1.5 assists and shooting 37.5 percent in his past four games. Evans has since been moved into the starting lineup and continues to rebound at a high rate. In Sunday night’s blowout loss, the Nets’ bench combined for 32 points -- their largest output since they combined for a season-high 52 on Nov. 18. In between, there have been a lot of duds.

4. Their backcourt doesn’t exactly look like the best backcourt in the NBA

For nearly $190 million, you’d think the Nets would be getting a lot out the “dynamic duo” of D-Will and Anchor Joe. You’d be wrong. Williams and Johnson have nine All-Star appearances between them. If either could actually hit an open shot, they’d have a chance to increase that total. Johnson’s point totals the past four games -- 12, 17, 32, 6 (part of why he was benched Sunday night) -- accurately epitomize his season. D-Will is averaging 24.7 points in his past three games -- albeit on 42.6 percent shooting. These two guys need to snap out of it. The Nets are paying them too much and not getting a proper bang for their buck.

5. Their 3-point shooting hasn’t been on point

In the past four games, the Nets have combined to take 120 3-pointers and make just 38 of them (31.7 percent). Brooklyn isn’t a proficient long-range shooting team, which is why it’s so surprising that the Nets have become so reliant on a shot they don’t make at a good rate. The Nets are at their best when they allow Lopez and Johnson to operate in the post and create offense out of it. That’s when they become slow and methodical, the half-court-heavy team that ranks 29th in the league in pace. But when the Nets begin bombing from deep, they end up getting into track meets with faster teams who capitalize off long rebounds with transition layups or dunks at the other end.