Injuries in Colts' secondary elevates Hayden to starter

With an already weakened secondary further depleted on Saturday, Indianapolis Colts second-year veteran Kelvin Hayden will make his first career start on Sunday, stepping into the left cornerback spot for the game against the New York Jets.

On the positive side, the Colts, who list eight starting-caliber players on their official injury report, figure to have kicker Adam Vinatieri back for the game. Vinatieri missed last week's game, the first time he has ever been sidelined by an injury, with a groin strain. He is expected to handle the placement chores, but not kickoffs, versus the Jets.

The elevation of Hayden to the starting lineup was precipitated by a concussion that will sideline Marlin Jackson, who on Saturday was downgraded from "doubtful" to "out." The Colts are also without regular starting left cornerback Nick Harper, who suffered a groin injury in last week's victory over Jacksonville.

Jackson, the team's first-round pick in the 2005 and challenging Harper for the starting job, played much of the second half last week and had a superb performance, not only in coverage but also in helping to shut down a Jaguars running game that dominated the Colts in the first two quarters.

But the concussion forced Jackson from the game late in the contest and kept him off the field for much of this week's practice time.

The injuries to Harper, Jackson and Pro Bowl free safety Bob Sanders (ankle), who will miss a second straight game, means Indianapolis will be without three of its top four players in the secondary. Mike Doss, who had nine tackles and an interception last Sunday, will again replace Sanders.

Indianapolis likely will be forced to use rookie Tim Jennings, a second-round choice, in nickel situations.

Hayden, 23, was a second-round choice in the 2005 draft. The former Illinois standout appeared in all 16 games, but with no starts, as a rookie, and posted 19 tackles and one pass defensed. He played as a reserve in the first two games of this season, and had one tackle, but did not dress for last Sunday's contest because of an ankle injury.

The decimated Colts secondary could face a tough challenge against the Jets' passing game that ranks No. 7 in the league and which is led by quarterback Chad Pennington, who is an early-season contender for comeback player of the year honors. Pennington has come back from two surgeries to his right rotator cuff and, through the first three games, ranks fourth in the league with a passer rating of 103.4.

Pennington has completed 65 of 99 passes for 808 yards, with five touchdown passes and just one interception.

Len Pasquarelli is a senior NFL writer for ESPN.com. To check out Len's chat archive, click hereInsider.