The Dallas Cowboys did a little window shopping Monday at Valley Ranch.

With not enough salary cap space available to sign any player, the Cowboys hosted three free agents on visits Monday to put them at the ready when – or if – they’re able to free up sufficient money to upgrade their roster.

Former All-Pro safety Michael Huff, safety Will Allen and linebacker Justin Durant visited Valley Ranch but left without signing contracts. Huff, who played in college at Texas and in high school at Irving Nimitz, is expected to visit Baltimore later this week.

The Cowboys have only about $100,000 in salary cap space available and would have to cut more players, restructure more contracts or sign quarterback Tony Romo or linebacker/defensive end Anthony Spencer to long-term contracts to free up enough space to sign any player.

The Cowboys are at work again this week negotiating with the agents of Romo and Spencer in an effort to strike long-term deals that would reduce the players’ combined $27.4 million cap hit for 2013.

Until one or both long-term deals are finalized, the Cowboys aren’t likely to make another move to free up salary cap space to strike in free agency.

Huff was the big name at Valley Ranch on Monday. Huff, who just turned 30 earlier this month, spent his first seven seasons in the NFL with the Oakland Raiders, who selected him with the seventh overall pick in the 2006 draft.

The Raiders released Huff two weeks ago to help them create salary cap space. Huff had two seasons remaining on his $8 million per year contract and was in line to receive a $4 million roster bonus just days after he was released.