issue have characterized the PLRA’s exhaustion requirements as affirmative defenses---- We need not answer this argument here”). Courts in other circuits have treated the PLRA’s requirements as affirmative defenses that must be pleaded lest they be waived. See, e.g., Anderson v. XYZ Correctional Health Serv., Inc., 407 F.3d 674, 681 (4th Cir.2005) (stating that “an inmate’s failure to exhaust his administrative remedies must be viewed as an affirmative defense that should be pleaded or otherwise properly raised by the defendant”); Johnson v. Testman, 380 F.3d 691, 695 (2d Cir.2004) (observing that “[t]he failure to exhaust available administrative remedies is an affirmative defense” and holding that “that this defense is waiveable”); Foulk v. Charrier, 262 F.3d 687, 697 (8th Cir.2001) (<HOLDING>); Massey v. Helman, 196 F.3d 727, 735 (7th
holding that under the plra an inmate must exhaust available remedies prior to filing suit holding burden of proof is on one asserting an affirmative defense recognizing that mitigation of damages is an affirmative defense a party must plead and prove recognizing that collateral estoppel or issue preclusion is an affirmative defense under fedrcivp 8c that is subject to waiver and forfeiture  and therefore holding implicitly that this defense is not an attack on the courts subjectmatter jurisdiction holding that the assertion that a plaintiff prisoner failed to exhaust all available administrative remedies as required under the plra is an affirmative defense under fedrcivp 8c it is the burden of the defendant asserting this affirmative de fense to plead and prove it