In fairness to the other shortstops, with the exception of Derek Jeter, Lugo's atrocious year in the field has to be added to the comparison.
WARP1
Young - 4.0 (TEX)
O. Cabrera - 3.3 (CHA)
Peralta - 2.6 (CLE)
Crosby - 2.0 (OAK)
Aybar - 1.7 (LAA)
Jeter - 0.9 (NYY)
Eckstein - 0.9 (TOR)
Bartlett - 0.8 (TBA)
Renteria - 0.7 (DET)
Lugo - 0.5 (BOS)
Betancourt - 0.1 (SEA)
Bynum - -0.4 (BAL)
Pena Jr. - -1.8 (KCR)
According to WARP1, Lugo would be tenth out of the fourteen SS in the AL. The Royals have already replaced Pena Jr. with Mike Aviles, who already has a higher WARP than Lugo. The Orioles are looking to upgrade at SS, as well.
If the field is expanded to the entire MLB, Lugo tumbles even further down the list:
Ramirez - 5.1 (FLA)
Reyes - 4.6 (NYM)
Young - 4.0 (TEX)
Hardy - 3.6 (MIL)
Escobar - 3.6 (ATL)
Cabrera - 3.3 (CHA)
Tejada - 3.2 (HOU)
Guzman - 2.7 (WAS)
Theriot - 2.6 (CHN)
Peralta - 2.6 (CLE)
Furcal - 2.4 (LAD)
Rollins - 2.4 (PHI)
Crosby - 2.0 (OAK)
Aybar - 1.7 (LAA)
Greene - 1.6 (SDP)
Wilson - 1.5 (PIT)
Drew - 1.1 (ARI)
Keppinger - 1.0 (CIN)
Jeter - 0.9 (NYY)
Eckstein - 0.9 (TOR)
Bartlett - 0.8 (TBA)
Renteria - 0.7 (DET)
Lugo - 0.5 (BOS)
Izturis - 0.3 (STL)
Tulowitzki - 0.0
Betancourt - 0.1 (SEA)
Vizquel - -0.3 (SFG)
Bynum - -0.4 (BAL)
Pena Jr. - -1.8 (KCR)
The Red Sox can certaintly improve production from the SS spot. The obvious solution is Jed Lowrie, who is hitting a fine .276/.363/.443 at Pawtucket, and in his time at the MLB level had a 0.7 WARP1.