The New York Jets have acquired the services of running back Khalil Herbert after placing starter Braelon Allen on the injured reserve. Allen is reported to be sidelined for an indefinite period after spraining his MCL on Monday night in the 27-20 loss to the Miami Dolphins.Before the official confirmation on Thursday, Jets coach Aaron Glenn discussed Allen’s knee injury on Wednesday, disclosing that the running back was seeking a second medical opinion. He noted that the team was not yet ready to decide on placing Allen on Injured Reserve."We're still going through exactly how we're going to designate that, so give me a little bit of time with that so we can try to figure it out," Glenn said on Wednesday. "We'll see exactly where he's going to be when it comes to designate whether he will be on the IR or not."With his designation on the injured reserve list, Braelon Allen will miss at least four games, a huge concern for the struggling Jets. This immediately led the Jets to sign free agent Khalil Herbert, who brings a significant amount of experience to the team's running back room.However, the outlook of the Jets' running back room has not impressed many NFL fans despite the signing of Herbert. Many have condemned the decision of Aaron Glenn to place one of the team's best running backs on the kickoff return team, eventually leading to his injury.Here's a look at some of the reactions online:Jets Afterburners Podcast @NYJAfterburnersLINK@nyjets Stupid move by Glenn placing your key RB on kickoffs...no es buenoBrian Fagioli @brianfagioliLINK@nyjets I feel like Braelon Allen should sue the jets for negligence. No lie.Jets71 @Warner97803HLINK@nyjets Brilliant decision to have Allen returning kickoffsSpencer Carter @spencerc59LINK@nyjets Glenn absolutely failed Braelon by putting him on KR. So sadThe truth @againstmentirasLINK@nyjets How about getting a receiver to help Wilson out!!! Not to get double team......Jutty @juttysticksLINK@nyjets Glenn came into the year talking about our running attack. Then put RB2 on kick return 🤣🤣🤣🤣🤣🤣🤣The New York Jets’ running back room after Braelon Allen's injuryWith Braelon Allen now expected to be out of action for at least four weeks, the New York Jets will turn to Breece Hall and Isaiah Davis for production in the rushing game. Before his injury, Allen had appeared in all four games for the Jets this season, rushing for 76 yards in 18 carries.Khalil Herbert is also expected to play a crucial role in the team's rushing game in the absence of Allen. Selected by the Chicago Bears in the sixth round of the 2021 NFL draft, he's recorded 1,905 rushing yards and nine touchdowns in his four-year professional career.Before Braelon Allen's injury, the Jets boasted the third-ranked rushing offense in the NFL. Hall leads the team's rushing stats with 238 yards, while quarterback Justin Fields follows with 178 yards. The team will look to keep its rushing game potent for the rest of the season.