Rex Ryan expects Dustin Keller back

Help is on the way for the New York Jets' struggling offense, which has produced only two touchdowns in the last three games.

Tight end Dustin Keller, who has missed the last four games with a pulled hamstring, is expected to play Sunday against the Indianapolis Colts, according to Rex Ryan.

"I'm encouraged," the Jets coach said Tuesday morning on a conference call with reporters, about 10 hours after a 23-17 loss to the Houston Texans. "When I talked to Dustin last, he felt he was going to be able to go this week, so I think that will give us a huge boost."

But the Jets have several other injury concerns. Pro Bowl center Nick Mangold (ankle), nose tackle Kenrick Ellis (knee), wide receiver Clyde Gates (shoulder) and linebacker Josh Mauga (pectoral muscle) were scheduled for MRI exams on Tuesday.

A league source told ESPNNewYork.com that Mauga's pectoral muscle is torn, ending his season.

Mangold returned to the game after Texans defensive end J.J. Watt rolled up his ankle on the first play of the third quarter, so the Jets are encouraged that he was able to come back. But Mangold has a history with ankle injuries. He hurt the same ankle last season and missed two games with the dreaded high-ankle sprain.

Ellis, who started for the injured Sione Pouha (back), suffered a likely MCL sprain, according to a source. Doctors ruled out an ACL tear, according to Ryan, but Ellis still is likely to miss at least two games.

The next man up at nose tackle is Damon Harrison, an undrafted rookie from William Penn (Iowa). He made his NFL debut Monday night. If Pouha doesn't play, they could use more 4-3 fronts to avoid having to use Harrison as an every-down nose tackle. It would be another blow to the beleaguered run defense, ranked 31st in the league (172 yards per game).

The Jets already are without their top playmakers on offense and defense, wide receiver Santonio Holmes (foot) and cornerback Darrelle Revis (knee), both of whom are out for the season.

On Monday night, quarterback Mark Sanchez played without his three primary targets -- Holmes, Keller and rookie wide receiver Stephen Hill, who may return this week from a hamstring injury.

The Jets managed 286 yards against the league's top-ranked defense, but they were undermined by dropped passes. Tight end Jeff Cumberland, who caught a 27-yard touchdown early in the game, let a high but catchable pass go off his hands with two minutes left in the fourth quarter. Cornerback Kareem Jackson caught the deflection for a game-sealing interception.

In the first quarter, wide receiver Jason Hill -- signed off the street only five days earlier -- dropped a perfect deep throw by Tim Tebow.

The receiver-needy Jets got a big game from Jeremy Kerley (five catches for 94 yards), but there's no question that Sanchez -- after four straight games with an under-50 percent completion rate -- misses Keller.

"There's no question that it's going to be great to get Dustin back," Ryan said. "You're talking about one of the better receiving tight ends in football."

Ryan said he's hoping Hill, out the last two games, will be ready as well.