For now, the team is listing Baas with a neck/intense headaches issue on the pre-practice injury report.
"It is much more serious than a headache obviously," Coughlin said of Baas, who was a late scratch for Sunday's game with headaches. "There is a lot more to it than that. As a matter of fact he is having tests even today. He has spent most of the last couple of days doing tests and a lot of that is to try to eliminate things as well. Until I am sure I am going to be talking about the right thing, I will wait and not (engage in) much speculation."
Baas was vague when asked about the injury on Wednesday.
"All I really have to say is that I've had neck issues that I've been dealing with pretty much all season. These issues have stemmed into kind of migrained symptoms," Baas said. "Now, we're getting a lot of tests done, some evaluations. We'll let the medical staff handle all that, you know, [and] make the right decision. I really want to play football but my health is more important to me."
Baas suffered a neck burner in Week 4 against Arizona. He was forced to sit the next week against Seattle. The center was evasive when asked if his current headaches could be related to a concussion. He didn't want to entertain questions about the injury possibly ending his season.
"I'm not thinking about that at all," he said. "What I'm thinking about is this week. And I'm going to do whatever they want me to do in terms of getting stuff tested out and looked at…. And go from there."
Coughlin said the neck and headaches are related. The Giants started Kevin Boothe at center and moved backup Mitch Petrus into the starting lineup at left guard. At the moment it does not sound like Baas will be ready to play in a huge divisional game against the Cowboys on Sunday night.
The Giants offensive line has been pounded by injuries recently. Left tackle Will Beatty underwent season-ending eye surgery and was placed on injured reserve. Backup tackle Stacy Andrews was placed on injured reserve on Wednesday after being hospitalized over the weekend with pulmonary embolisms in both of his lungs.
Andrews is expected to make a full recovery. The team signed former Colt Tony Ugoh, a 6-foot-5 and 304-pound tackle who made 27 starts for Indianapolis between 2007-09. Ugoh was with the Lions last year and played for Las Vegas in the United Football League this fall.
In other injury news, tests on safety Kenny Phillips' knee revealed an MCL sprain. He is optimistic about the possibility of playing on Sunday.
"I haven't been told I'm going to miss a game, or miss anything. So right now, I've got a positive attitude," Phillips said.
Phillips underwent surgery to repair an arthritic condition in his knee in 2009. But he said the current ailment has nothing to do his previous injury.
Baas and Phillips joined a host of Giants who did not practice due to injuries on Wednesday. Linebacker Michael Boley (hamstring), running back Ahmad Bradshaw (foot), linebacker Mark Herzlich (ankle), running back Brandon Jacobs (hamstring), linebacker Spencer Paysinger (hamstring), defensive end Dave Tollefson (knee) and Osi Umenyiora (ankle/knee) did not participate in practice.
Umenyiora likely will miss his second straight game due to a sprained ankle.
Ohm Youngmisuk covers the Giants for ESPNNewYork.com. ESPNNewYork.com's Ian Begley contributed to this report.