One car that won't be appearing at this weekend's STP 300 Nationwide race at Chicagoland is the Joe Gibbs Racing #20 Toyota, despite the car having a 15-point lead in the owners' points table. The car had been due to be driven by Joey Logano, who will be driving in the Cup race at Kansas on Sunday.

Meanwhile the team's #18 car normally driven by Kyle Busch will instead be under the control of Kelly Bires, while Busch focusses on the Cup and Truck races in Kansas.

Joe Gibbs confirmed that the withdrawal of the #20 was due to a lack of sponsorship, and that the car would no longer be making regular series appearances.

"We entered the car before we put everything together and realized it couldn't work," Gibbs admitted.

"We're still going to run a lot with the #20," Gibbs insisted, "but right now, we don't have the money lined-up to go the whole way and we were fortunate and thankful to get as far as we did - running the whole year.

"Both cars are kind of in the same boat. We're just going to go as far as we can and as long as we can go and just kind of see where it goes. We've kind of been blessed to get where we are with the #20 and the #18, and they've got some more [sponsorship] lined-up, but there's still some empty races that we'd love to fill, but we don't have to fill."

The withdrawal of the #20 together with the absence of the #04 Go Green Racing Ford means that only 42 cars are entered for the 43-car maximum race.

Meanwhile Pastrana-Waltrip Racing also confirmed that their funding shortfall had now reached the point where rookie Ryan Truex's #99 car will also now been forced to go part-time and may be limited to as few as eight of the 20 remaining races in the 2011 season.

"Ryan is really starting to mature in the seat and the team is starting to gel," said team co-owner Blake Bechtel. "He deserves to run every week so that he can keep getting that valuable experience. We will entertain and pursue other opportunities so that we may race more than the existing commitments."

"Yeah, it's a little disheartening when you think about it," Truex said. "These last four races we've really hit our stride and started running good."

19-year-old Truex - the younger brother of Sprint Cup driver Martin Truex Jr. - is still entered in this weekend's race at Chicagoland and says he's still looking for opportunities to continue his drive.

"We're doing all we can, but luck hasn't really been on our side."