The Cowboys could lose two defensive starters as soon as Thursday with safety Barry Church and tackle Terrell McClain likely to exit as unrestricted free agents.

Church has reportedly agreed to a four-year deal with Jacksonville. Church, 29, has spent his first seven seasons with the Cowboys, starting the last four. The defensive captain annually ranks among the team's leading tacklers.

Last season, Church finished second in tackles with 109 and led the Cowboys with two interceptions.

McClain, a starting defensive tackle for Dallas in 2016, has received interest from multiple teams during the NFL's two-day negotiating window that precedes the official start of free agency at 3 p.m. Thursday, according to a source.

Multiple teams that use a 4-3 defensive scheme have inquired about McClain, who finished last season as the club's leading tackler among defensive linemen with 41 stops. He also had 2 1/2 sacks, eight quarterback pressures and two forced fumbles in helping to solidify the interior of the Cowboys' line, allowing Tyrone Crawford to move outside to end.

One team that has showed a lot of interest early on in McClain is the San Francisco 49ers.

McClain would fit the 49ers' scheme and rejoin Jeff Zgonina, the 49ers' new defensive line coach. Zgonina played 17 seasons in the NFL as a defensive tackle, finishing his career with the Houston Texans in 2009.

Zgonina was hired as the Texans' assistant defensive line coach in 2013. McClain played for the Texans in 2012 and 2013 before signing with the Cowboys, where he's spent the last three seasons.

Jacksonville is also reportedly interested in McClain, who's from Tampa.

McClain, 28, is well-liked among his teammates and every Friday, while the team stretched before practice at The Star in Frisco, he'd break out in a dancing routine at the front of the line.

McClain only played two games in 2015 for the Cowboys because of injury but started 15 games for Dallas in 2016. It was McClain's first season to start since his rookie year for Carolina in 2011, when he started 12 games.

McClain is one of the Cowboys' 18 unrestricted free agents, down to 17 with wide receiver Brice Butler reportedly agreeing to a 1-year deal for 2017.

The Cowboys aren't in position to pay big money for any player, with only about $8.5 million in salary cap space available to them after restructuring the contracts of offensive linemen Tyron Smith and Travis Frederick and linebacker Sean Lee.

Twitter: @DMN_George

Briefly

The Cowboys were represented Wednesday at Alabama's pro day by longtime scout Walter Juliff. Patriots coach Bill Belichick and Seattle coach Pete Carroll were also on hand. ... Cowboys unrestricted free agent safety J.J. Wilcox is reportedly receiving strong interest from Tampa Bay. If the Cowboys lose Wilcox and Church, reserve Jeff Heath could end up starting opposite of Byron Jones next season at safety if Dallas doesn't turn to the draft for help. ... The Cowboys also might not be able to re-sign cornerbacks Brandon Carr and Morris Claiborne who hit the open market Thursday.